Front End Clunk - Cross-Member Bushings

[GMCanuck]

New Guy here - well kinda. Now that I own a 2006 Sierra, I decided to revise my user name. But either way, glad to be back on-board...

After searchig for a while for my front end clunk - I FINALLY FOUND IT ! ! ! ! !

Turns out that the bushing at the end of the cross-member where the rear of the torsion bar mounts is loose (see photos). The torsion bar is firm in the cross-member, but there is alot of movement and knocking in the connection where the cross-member attaches to the frame. The cross-member moves up and down when I lift the vehicle from below. And since the rivets holding the bracket to the frame are tight, I am assuming the bushing is worn.

I've searched a bit and seen other references to this issue, but I'm looking for some help replacing these. So, anyone have any experience with replacing these parts? Can this be done with the torsion bar and cross-member in place?

I've spoken with a dealer and it turns out that the new bushings come complete with the bracket that bolt to the frame. So it will just be a matter of grinding/cutting the existing rivets and bolting the new one in place. But can this be done without loosening the torsion bar? Just simply supporting the cross-member during the time the bushing/bracket are out?

Any thoughts or help would be appreciated.