DIY. I used a engine leveling tool, a floor jack for the transmission and a pry bar. If you pull the trans and engine as a unit, it may be easier to install as a unit. I left my trans in (the car), but used a floor jack to raise it as high as it would go. When installing the engine, I tilted the engine slightly down in the front (so the back end was facing slightly up). When lowering the engine, get the motor mounts close, you can use a pry bar to adjust the position (especially if you're using rubber mounts). Don't pry between the block and the mount and pry just enough to move the mounts. When close, begin to level the engine and lower the trans. Both the trans and engine should fall together. Yes a helper would have been nice,but I was alone for both my 383 Chevy (for the Chevelle) and the Buick engine. Never had a problem. The factory motor mounts have quite a bit of flex. I would advise taking the time to mark wire and vacuum hose postions before removing the engine. Also, you want to stand the hood straight up or remove it (I stood it straight up). Personally, unless it's tranmission rebuild, body and paint, front end alignment or exhaust work, I'm the only one who repairs my car.