ntdsutil is tricky and not very intuitive.
A few suggestions:
1/ type "?" at every level for additionnal info, "q" to return to the previous menu
2/ Connect first to your domain by typing "connections", then "connect to server <server name>", where server name is a valid DC to whom you want to transfer roles. This connection is NOT a default for ntdsutil. then type "q" until you return to the first menu
3/ in your case, type "roles" to get the "fsmo maintenance" prompt
4/ type "select operation target" because it doesn't default to your current domain
5/ whenever you select something, like a domain, a server, a site , etc... you type first the "list" command, then the "select" command. The "select" command usually requires a number (not a name!!) . Example: "list server in domain", which returns a number followed by a name. you must type "select server <number>", like "select server 2" for instance
7/ in your case, type "list roles for connected servers"
8/ in your case, type "seize ..." whatever role you want
Good luck