Hi there - My Power up valves need replacing. I have bought some new ones and decided i will give it ago myself. Dont know if my amp needs biasing but i'll soon find out. Anyway i was wondering if someone can give me a fairly detailed description on how to change my valves. This is my first time. Firstly - To take out my previous ones (some one said to me just pull them straight out - i tried and they seem pretty stuck) Secondly - saftey procedures for putting in the new valves - is it true that i should not touch them with my skin at all??? Im urgently trying to fix this as i wanna play!! Thanks!