2 quick questions regarding my 72

[Quackaddict]

1. Pulled the water pump off to replace it and for the life of me I can't figure out how to get the spacer and pulley off to put on the new pump?????

2. I was doing some disassembly this weekend and behind the battery tray mounted to the fender is a black canister with a hose on it that is disconnect what is this, is it important, where do I connect it.

Thanks for the help.