Hi all. I’ve not long purchased a 2011 Beta evo 250 to start my trials career. But ive now noticed the oil in gearbox is milky.I’ve changed it a couple of times but keeps coming back so I’m thinking possible water pump seal.So ive purchased one.I know how to get to the seal but wondered what’s the easiest way to pull the old seal out.Am I able to drill a small pilot hole in it to put something in to pull it out or is there a easier way.Thanks in advance.

you probably find the case is perforated with pin prick holes, I had two that this happened to, easy to replace though

A self tapping screw will work. 

Case will be fine if it's had anti freeze in it,  my 2012 has no corrosion. If it's only had water then it might have corroded through.