Driver side door can't lock/unload w204

Hello Mr. Senior Leigh,

Well my wife 2010 C350 W204 gives me a few issues. And after I get them all fix. And now another issue.

Today we just found out the drive front door will not lock/unlock with keyless entry and or pressing the key fob.

The other 3 doors no problem. If I put my ear close to the door. I hear some motor noise when I press the key fob and that about it.

Now we have to open and lock the door with the key and no other method/way. I look at some video and is very hard to replace the actuator. Some say just an option to get an after market Actuator just under $ 20.00 and connect and mount it inside the door panel. Cut 2 wires that give power to the oem actuator and connect to after market one and done. Do you think this is a good cheap option to get this fix. And also how to lub the drive power seat. It sound louder then I expected when I most the seat back and fore.

Can I reach the gear under the seat or just spray some greese on the seat tract.

Thanks !

Spencer Chan