K7 Focus Screen

Have a bit of black "stuff" and what appears to be a very small hair on the focus screen. How do I clean this. Do I need special tools? Any help appreciated.

The Pentax K7 also stands to earn praise from the Pentax fan base thanks . Four interchangeable focusing screens are available.

EDIT: (Advertising removed by moderator)

Stan,
I normally use a 'Rocket' blower

EDIT: Pentax User have one such on sale here!

When using such a blower, make sure you pump it hard a few times before using it to blow off the crud in the camera (otherwise you can end up blowing more dust onto the mirror & screen).

Whatever you do, don't touch the mirror... and preferably not the focus screen either (as they're easily damaged).

Matt

Thanks to all who replied. I chickened out, thinking of my eyes, nerves, how things tend to break in hands for no reason etc., and took it in to a camera repair shop in Newcastle where a kind gentleman did the job for me at no charge ( I put a couple of quid in the lifeboat charity box on the counter ) so if anyone has a camera to repair sensor to be cleaned etc., I can recommend:

APM Camera Repairs, 6 Old Eldon Square, Newcastle