722.300 280SE first gear start on valve body.

[Rishiganasen]

am planning to remove the valve body on a 126 280SE. the transmission is a 722.300.and i am intending to do the first gear mod.whats are the steps to remove the valve body from the transmission and have heard that people swap the spring in the govenor pressure boost valve. has anyone really did this mode before? and also its my first time touching and dismantling a transmission valve body