Can you move the items from the Trash to the Desktop, or to another volume or does that also fail ?
Are there odd characters in the items names by any chance ? If so drag them out, name them "rubbish1", "rubbish2" etc then put them back in the Trash and delete again.
OK that's sounding like Permissions - Get Info on them and then look at 'Sharing & Permissions' at the bottom - try and set Read & Write for them all (you might be asked for admin password)
If the Time Machine icon isn’t in the Dock, look for Time Machine in the Applications folder.
Use the arrows or the timeline along the right side of your screen to browse through the backups Time Machine has created.
The windows behave just like Finder windows, so you can open folders, click items in the sidebar, and use the search field in the upper-right corner of the window.
When you find the item you want to delete, select it, and then open the Action menu (looks like a gear) and choose Delete All Backups for the item.