what exactly are you trying to replace? the clutch bearing (pulley/rim bearing)? if you are, i am going to do the exact same thing. i have ordered a # of tools for the job.
99-454 GM A6 and R4 Clutch Plate Remover
99-458 GM A6 and R4 Clutch Plate Installer
99-350 GM R4 Compressor Bearing Remover and Installer
22-1058 GM Staking Kit Bearing & Pulley Installer
these are the tools i ordered for the job. if you need any other A/C tools check these guys out....
MVPRO.COM
there toold are resaonably priced.
p.s. i'll let you know how it goes.......