Changing the Racors on the dual filter set-up I have, I check bowl for water or crud, so far after 2 years nothing but fuel in there. I take lid off filter to be changed, pull out filter slowly, insert new, change gasket spin top back on. Lever on filters is on non changed filter. I then start engine, idle up to 800-900 rpm, then switch to just changed filter, if engine stumbles or loses rpm the I quickly change lever to other filter. After a few times all is good. Filter on front of engine, I spin off old spin on new, lubed o-ring. I either loosen bleeder plug or leave filter loose. I have someone on bridge turn on key, wait for pump to fill filter and start to dibble out, have them shut off key, tighten bleeder or filter, then restart, and check for leaks. I can fill Racors with my transfer pump, but as yet have not needed to.