How to clean print head To see if my machine will then work

I’ve done it before on the HP 564 printers I’ve had (new, and ones I’ve literally pulled from the trash for a guide) and cleaning resolves it most of the time, but yes it’s not a 100% success repair.

The problem with yours is you’re stuck between a rock and a hard lack - not something easy to fix, a properly difficult one :(. Yours is the “permanent” type where it needs to come apart, so you lost your calibration for the head as it stands and it will probably demand “Setup” ink, and there’s a chance it wants the ones the printer shipped with. Unless you can get into the manufacturing menu (not easy - on the ones I had before I gave up on inkjet flat out you held the power button down but I forgot the other buttons you’re supposed to hold) and change the SETUP requirement to false, you’re dead in the water.