Where to buy Adjustable Spanner

brt, in case you haven't purchased your adjustable yet, you'll need another tool to assist with tightening of anything. It's a common problem with adjustables.
Go in to one of the many TOOL shops and ask them for 'A long weight'.
This should help you out.

And striped paint, don't forget striped paint.

Also, when installing new parts, especially with a metal to metal contact, it's good to use some grease, I find 'elbow grease' the best.