If you can drain and refill, it's VERY likely you can start up with no problems. And, if you are OTO-orange, with CYA=40, then draining might be the best idea.

Have you drained before? Do you understand the danger of the walls collapsing inwards?

Also, you need to understand you'll STILL have some chlorine resistant algae left in your pool -- you'll eliminate 90% or more of both the algae and the goop, but we'll need to make 100% that the remaining algae DIES as you refill.

You do realize you'll have to buy a number of additional chemicals? Probably your best bet for startup, if you can get access to a Sams Club, is their PoolBrand 24/pack of dichlor for about $50.