The Graphex shutter came in 3 versions, no flash sync, full flash sync, X flash sync only.
The linked service manual is for the full flash sync version. The X flash sync version flash sync is similar but simpler.
The no flash sync version has no flash sync parts and the steps for the flash parts can be skipped.
The shutter will die and may not be repairable if used until it stops working.
White lithium grease works fine where grease is called for.
Watch oil, gun oil, TriFlow are good oils for shutters.
Extra fine powdered graphite can be used on the shutter and aperture blades especially on their pivots.
Too much oil or grease acts like glue and slows a shutter down.
Take pictures as you disassemble the shutter, it makes reassembly easier.
Alternative, send it to me for servicing.