The problem is that you aren't the only Jim on this forum, so numbers are added to your name to differentiate you from all the others. Using first and last names or another made up screen name that isn't just a first name will allow you to pick your own.

Thanks, I will just leave the 888 on it

They automatically add numbers when you enter a name that’s already in use. So you may want to figure out what you want to change it to.

To change it, click on the three grey bars on the upper left hand corner, settings, account setting. Changing your name is the fist option. It’s a good idea to let your freinds know.