rear main seal

[engatwork]

I have determined that my rear main seal is causing my oil leak (98k miles). I have discussed the repair with the appropriate people and know what it will take to pay to have it replaced. I have pulled engines out and put them back in before but have never removed/replaced an automatic transmission wihtout removing the engine. Based on what I can tell by looking around the tranny and reviewing the appropriate manuals it looks like a pretty straight forward job. Essentially, from what I can tell, replacing the seal is the easy part - it is the R&R of the tranny that takes the time. How tough a job is this for a competent diyer? What is the hardest part of this job other than the grunt work? Would it be easier to remove the engine and leave the tranny in place? Can I get to the seal to replace it properly if I only remove the tranny?
thanks,
engatwork
'95 E320
'97 Honda CRV