Corny keg/fermentor

So I was super lucky to score 12 conrnys for $160 last weekend! I plan on using some for bulk ageing some sours and would like to use a few for primary fermentors(mostly 4-4.5 gall SMASH batches). I have looked all over the net and there are a ton of builds for blow-offs and what not, but nothing really simple and definitive. I have some extra grey QD's and hose and I would like to not have to take the post out because I want to push using CO2. Does anyone have a good workup or a link? I can get my hands on whatever additional equipment may be needed, thanks in advance!

I do 10 gallon batches in a 15 gallon corny. With that kind of head space, I'm pretty comfortable hooking up the gas disconnect with some hose attached to it going to a mason jar with star san in it. Works fine. I think the purpose of removing the poppit is to keep it from getting gummed up in the even of a blow off.

Just sanitize the keg as is, but do yourself a favor and remove the liquid tube. Mix up your posts or QD's and that keg will empty everywhere. trust me, you'll only do it once. Use fermcap to keep the krausen down. When it comes time to transfer, replace the liquid dip tube and pressurize to 5 psi. Use a liquid to liquid jumper and you can transfer to a clean keg.

Tip:
Use swivel connectors and take one QD off the jumper so you can bleed off the first pint of sediment. Then pull the liquid out QD on the original keg so you can stop the flow. Hook up the second QD again to the jumper. Transfer as normal. Easy peasy.