It's no great problem but it helps to have either a good lift or garage pit for access.
I have only ever removed the sump when replacing the water pump but from memory I think I had to remove the starter motor, rear flywheel shield and exhaust to get access and slide it out.
You can get the bolts out with the shield & starter removed but I couldn't get sufficient angle to slide it forward. Mine is a home made exhaust and the routing might be different from the Lotus pipework, so I'd try to slide it out before pulling the exhaust pipework.
In places the access to the sump bolts is tight, if you have a good set of extensions then 1/4" drive sockets are ideal.
Brian
edit to add - I see I've just been beaten on the 1/4" drive.....