What are some of the things that must be done by and for the prisoner before he can escape?

Tom decides that he and Huck will have to saw off the leg of Jim's bed in order to free the chain, send him a knotted ladder made of sheets, give him a shirt to keep a journal on, and get him some tin plates to write messages on and throw out the window. To top it off, Tom tells Huck that they will use case-knives to dig Jim out, rather than the much quicker and more appropriate picks and shovels.