An exploded view of the heater controls for a 1989 Olds Cutlass can be found in the Cutlass service manual. The manual can be found at most auto parts.
A diagram of the heater core of a 2001 GMC Jimmy can be found in the service manual. It outlines the location of all the components and how they are connected.
this is not a fun or easy job; i know from experience I would suggest the best thing for you to do, if you wish to do it yourself, is to order a factory service manual from a Chrysler dealer. The service manual gives detailed instructions. Alternatively, you can get a haynes Automotive service manual and follow their instructions
1981 Corvette Shop Service Repair Manual Book Engine Drivetrain Electrical GuideTry eBay for this Manual
Depending on what type of filter you have. For example, a Hayward S180 uses 150lbs of sand, S244 uses 300lbs. This information is provided on the sticker that is located on the tank of the filter.
Read the owners manual.
Get a workshop manual for the pump and follow the instructions.
You will be better off if you buy a service manual or borrow one from a library. You have to drain the freon, remove the entire dash, remove the heater/ac housing, and dissassemble the housing to access the heater core.
Go buy a service manual. This procedure is difficult. It includes taking the whole dash off.
No.
No mention of a block heater in the service manual. It appears that they install heaters on the left side rear of the engine. Of course this type of heater plugs in to household power so if you have one it should be fairly easy to find the cord/plug and trace it back to the heater.
The heat exchanger is the most expensive part to replace in your heater. The recommended thing to do would be contact a professional and have it installed. Maintaining proper water chemistry is the key to not having to replace it again. I have seen them be ruined in less that a week due to improper balance. Find your owner's manual that came with the heater and they give explicit advice on taking care of your pool heater.