You could also invoke "Enter Time Machine" as root. That requires Finder to be started as root first, so only for those who understand the risks. In Terminal, for both Leopard and Snow Leopard:
sudo /System/Library/CoreServices/Finder.app/Contents/MacOS/Finder
In Snow Leopard this does not (always?) open an initial Finder window. Do not click the Finder icon in the Dock (which might take you to your normal Finder), but use Command-Tab to go to Finder (which will be the new root-Finder). Here, hit Cmd-N for a new Finder window.
The new Finder looks like a normal Finder, but you'll notice root next to the home folder icon in Finder's sidebar. While the root-Finder is active, enter Time Machine (and once again validate that root is shown next to the home folder icon). This should allow you to browse, delete or restore what you need (but, for the original question: it won't solve your access issues permanently).
(As usual, holding down Option while clicking the Time Machine icon will change "Enter Time Machine" into "Browse Other Time Machine Disks" if you need to examine a disk that is not associated to your current machine. You might not need to be running as root to do that though!)
When done, eject the Time Machine volume if applicable. Next, hit Ctrl-C in Terminal to stop the root-Finder. The usual Finder will still be running, but in Snow Leopard the indicator in the Dock may have gone. Run killal Finder if that bothers you. (And if you forgot to eject the Time Machine volume while you were still root and the disk doesn't unmount properly at a later time, or if Time Machine won't mount it correctly when running its hourly backup, then you may simply log off as an easy fix.)
(If anyone knows how to do this without first running a root-Finder then please tell us! Running sudo "/Applications/Time Machine.app/Contents/MacOS/Time Machine" does not give the expected result, and I assume that the Time Machine galaxy window is in fact part of Finder. For the sake of search engines: "run time machine as root", "start time machine as root".)
If all you need to do is properly give permission rights, to specific users, over a drive then I recommend using a "Take Ownership" context menu. It will save you dozens of clicks and a reboot or two.
It's worked for me in regards to internal/external drives and foreign/native users. Needless to say I haven't used anything else for quite some time. You can take ownership of files/folders in bulk and I've found it's more efficient at granting admin privileges than manually doing it.
It's a 1KB file so it doesn't take longer than 5 minutes to get the job done (depending on how many files you're taking ownership of). Check it out here: http://www.howtogeek.com/howto/windows-vista/add-take-ownership-to-explorer-right-click-menu-in-vista/
--- Raw info ---
Add Context Menu by saving as .Reg file, then execute.
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\*\shell\runas]
@="Take Ownership"
"NoWorkingDirectory"=""
[HKEY_CLASSES_ROOT\*\shell\runas\command]
@="cmd.exe /c takeown /f \"%1\" && icacls \"%1\" /grant administrators:F"
"IsolatedCommand"="cmd.exe /c takeown /f \"%1\" && icacls \"%1\" /grant administrators:F"
[HKEY_CLASSES_ROOT\Directory\shell\runas]
@="Take Ownership"
"NoWorkingDirectory"=""
[HKEY_CLASSES_ROOT\Directory\shell\runas\command]
@="cmd.exe /c takeown /f \"%1\" /r /d y && icacls \"%1\" /grant administrators:F /t"
"IsolatedCommand"="cmd.exe /c takeown /f \"%1\" /r /d y && icacls \"%1\" /grant administrators:F /t"
If you change your mind you can remove the context menu this way:
Windows Registry Editor Version 5.00
[-HKEY_CLASSES_ROOT\*\shell\runas]
[-HKEY_CLASSES_ROOT\Directory\shell\runas]
Best Answer
You mean "root"?
I think you intend to give an administrator permission to a user. Simply, from System Preferences > Accounts > Then select "Allow user to administer this computer". You will need admin privileges yourself to set this for someone else.
Here is the documentation from Apple on creating new users.
Take it easy :)
Cheers.