While not all encompassing, this is a good little how-to. I must warn
you. If you have not done this before, there is a risk of injury from
high voltages so be forewarned and read up on discharging the CRT. Good
luck.
Make sure the replacement is not dated in summer of 2004. Apparently most
of that batch are failing. This is one case where I might look for an
aftermarket sub, preferably from HR. However, it is best not to mess with
it if you don't have experience working on television output stages.