Garrard 'Unimech' deck mechanical fault

[Crackle]

A 30 to 70 watt soldering iron is good for this job, so long as the item you are heating is not plastic. You can put the heat exactly where you want it without fear of burning or scorching.
It softens the hard grease and enables you to take apart to clean thoroughly before re-lubricating with the correct lubricant.
Yes WD40 or white spirit will help dissolve and clean off the grease, once you have got the parts apart.
Mike