You didn't bother to make the make of machine clear and didn't mention the model at all, so we are guessing.
Look at the machine.
Is there anything like an arm - probably at the needle end of the machine.
The arm should have a plate covering the gubbins behind.
How is the plate fixed on? Two screws?
Bingo.
If not repost with enough information for someone with no idea what you are talking about to understand.
dsagdsaf, July 2018