Have a 2008 525EFI in our Sunsation with a Hardin Marine Stainless pump body. Replaced the impeller, wear plates and the two O-rings and noticed that there was a slight leak. Water was coming out of the weep hole abeam the shaft that goes to the pulley. Took entire unit apart to ensure O-ring remained seated and it was all good. What's next? Take the entire assembly off and look at seals around shaft? Can I just remove the main gas line and gas line to fuel water separator without having to worry about pressure or continued gas spillage or pressurizing the system upon completion? How do you replace seals around pulley shaft?

Thanks for any and all help!

Any ideas?

If they are anything like the mercruiser designs then there are two shaft seals inside the pump. And if you are leaking water out the weep hole then the inner seal is going bad. To take the pump apart you would need to take off the pulley (if it's bolted on and not pressed on then you also need to remove that adapter the pulley bolts to (its pressed on the shaft))
from there you should find the first seal/dust cover. Flat head screwdriver gets it off quick. Then there should be a snap ring you remove and the entire shaft and bearings should slide right out and you can get at the final seal inside the pump. Then re-assemble in reverse order....

625-4204i.pdf
check this out...its probably not the same pump you have but the concept of repair is the same....

Also measure how far the pulley/arbor is in the shaft before you disassembled. You have to put it back in the same location for the pulleys to be aligned.

check out this old thread How To: Rebuilding Merc Sea/Fuel Pump
...should help you...and no you shouldn't have to do anything special with the fuel lines...they will bleed the air out themselves.