My primer is getting intermittent. Generally on the first start of the day it will feel solid and pump well but on subsequent starts it has no resistance and won't draw fuel. I've searched and found a lot of information for changing the o-rings in the newer style primer but this is the very old type shaped like a "T" with leather packing.

Looks like this I found online:
I took the big nut off but getting the plunger assembly out wasn't obvious to me and I didn't want to force it before doing some research. Any hints on disassembly and servicing?