Outer Limits 4x4 Board

I started my auto conversion this weekend, got the old 4speed manual out and noticed the rear main oil seal has a bit of a leak so I might fix it if it can be done without to much work. The work shop manual has installing the oil seal as part of refitting the crank, with a seal guide and a few steps of torqueing up bearing caps afterwards.
I'm wondering if it can be done insitu the block is a late 4.6 .