I will include an extremely specific instruction sheet designed to walk you through this, but this is a pretty complicated repair, so if you don't have much experience with this, buy the kit and take it to a professional. You should definitely have a fair amount of soldering experience and have a decent soldering iron, a dim-bulb tester, and heat-sink compound, as well as the usual tools. This kit may not fix your Marantz if it has other issues, but it will definitely help it run better, and should fix most amp board problems. Please see my pictures for details.
US shipping and handling is $5, and international is $18, no matter what quantity you buy. All my small parts are set up for combined shipping, so just use the "add to cart" feature and then check out all at once, and it will combine shipping. If you have any questions, please ask.