Disassembly:Sinclair Spectrum

A Spectrum 48K is easy to disassemble:

Remove the five screws from the back. Carefully open the case then lift the front edge you will see the keyboard connections to the motherboard, ease these connections out because they are easily damaged. It is advisable to spray the connectors with contact cleaner before trying to disconnect the cables.

Note that if the Keyboard is the original it is likely to be non-functional.