what to do?

If you have never done it, and you dont have the tools or experience in old auto repairs... I'd pay the pro and see if they will let you watch. The only reason I say maybe have them do it the first time is if you've never done stuf... Like freeze plugs... and you mess it up (it happens...) then you wont find it until the engine is in the car which makes thigns 100% harder when you've rented the lift and stuff. I dont know what your level is, which is why I say that. If you've got some experience on old cars doing m ore than driving and oil changes and you're confident you can take the time and get it right, get the books and do it. But expect to pay for some tools you dont have to do it properly.