Well, this is one thing i have lots of experience of!!.
Ive been doing for the last two years with some new engines we are developing for the RNLI/MoD.
And yes that is the right way to do it and its surprisingly easy to do.
But it would be quite hard on a big rib but you can do it if you have enough people.
I would show you some pictures of me rolling some RIbs but i dont know how to put them on this web site!!