I feel a bit embarrassed having asked the question but I had to ask!
The only silly question is a question not asked Ren!

If you can't get around the belly either sit on the loo and try or put on foot on the loo or bath and check that way, it's easier.

My midwife described it like you measure until you cant move your fingers apart anymore but if you can still feel cervix then measure the rim of the cervix and if there is say 2cms of rim then your 8cms dilated, etc.