Need help with differential mounts!!

[Bone_Stock_Supra]

As everybody knows, the diff. is held in place with two front bushings and two rear bushings that actually go through the sub-frame. I recently blew the passenger rear bushing out so I have been driving around with the front two and the driver rear holding in the differential. I recently purchased the replacement bushing and the allen-head bolt that holds it in and took it to my local mechanic. He removed the exhaust and even dropped down the swaybar but could not get the bushing pressed into the subframe. Has anybody had this problem? How do you get the bushings into the subframe? Any DIY guides would be very helpful. Thanks!