I now there are two methods:

I now there are two methods: using facer or watchmaker for all tethered watches or using clockskins for non tethered watches like the lem5. The clockskins can be unzipped in the folder clockskin while you can use your phone to send a .watch file to the tethered watches.
The funny thing is: if you change .watch into .zip you can unzip this file like any zip file and contains similar files like the clockskins.
my question is: can the .watch files be altered to become clockskins? If so, all .watch files can be used on non tethered watches too. Anyone willing to give it a go?

yes you can but only thing you can do is to extract the image files to make a clockskin watchface, same for apk watchfaces or widgets watches (zooper, uccw, kwiget) you can rename them to zip and extract the drawable resource files and make the clockskin xml script to get a working watchface, is pretty simple.

but you need to ask for permission to post your ported watchfaces here.

Thanks for the response Jorge Luis

@Sg_Houtman ClockSkinMaker can import all the graphics objects from .watch files, but nothing more.