Aircooled VW South Africa

I have just changed the oil in my 1600S. It was my mothers car and I suspected that it had not had an oil change in a long while. My suspicion was correct. When I took the oil drain cover off, it and the strainer were covered in a muddy oil/grease muck. I did the oil change and with a few km's checked under the car and found what appears to be a leak at the valve cover on the one side. It would appear that the previous oil was so thick that it wasn't leaking anywhere but the new oil has found somewhere to leak out.
I have looked up on you tube on how to change the gasket but everything sort of skips the removal of the cover so I need to know if I have to drain the oil before I remove the valve cover or if the oil doesn't reach that level when the engine is not running.
Secondly the covers are humingously rusty so I want to strip them and respray them. Anything to avoid when doing that?
Any advice will be welcome.

You can take the covers off without draining the oil.

You will though get 10 or 20 ml coming out so use a drip tray or old bucket to catch the few drips.

On your spray job, go ahead, but do not spray the inside or where the gasket sits.

When you remove the old gaskets, be sure to clean the surface properly & then glue the new gaskets into place.

We do have them in stock should you need.

This is what I do and not a leak, ever, stay away from aftermarket covers, the stock German item with bail is the best.
Save yourself some grief and get the covers blasted & powder coated, a lot more cost effective than prep & paint.
Use cork gaskets, there is plastic/rubber crap that I will not use even if they are for free.
Modify the tip of the bails by bending the tip of the bail (piece that goes into the head) Vice and hammer required, only need tips bent in about 2-3mm, this helps put more pressure on the gasket. The bails will be a little harder to get over the covers, but will create a seal that will be 100% leak proof.
Gaskets get a thin film of grease both sides no sealer, glue etc. needed, and the plus is you can pull the valve several times before the cork gasket needs replacing, no mess, easy.
I Got German Elring gaskets R80 for a set, shipping R35.