On my 97 SL320 to change the shifter side bushing I used a open end wrench on one side of the linkage lever, the bushing on the other then clamped the whole stack with needle nose vise grips to give it a push. The needle nose slightly distorts the bushing allowing it to fold into the hole and the open end wrench gives the bushing somewhere to go.

Lube the bushing with silicone grease to ease install.