IBM maintenance manual

The IBM 5100 Portable Computer is one of the first portable computers, introduced on September 9, 1975, six years before the IBM Personal Computer, and eight years before the first successful IBM compatible portable computer, the Compaq Portable. It was the evolution of a prototype called the SCAMP that was developed at the IBM Los Gatos Laboratory and Palo Alto Scientific Center in 1973. Although it was marketed as a portable computer, it still needed to be plugged into an electric socket.

Quotes

All parts should go together without forcing. You must remember that the parts you are reassembling were disassembled by you. Therefore, if you can't get them together again, there must be a reason. By all means, do not use a hammer.