If you are truly unsure about doing it yourself you could take it to your LBS. It's not very hard but some people don't have the right tools to do something like that. They will be sure to cut it down to the right length for you and they will do it correctly. Also....if you purchase things from them regularly you can probably get this easy job done for free.
yea. just use a hacksaw or a pipecutter. sometimes if you have the right blade a wet table saw will work. but just cut it then file it smooth. best to use a flat bastard file