Your best bet initially is to leave the penetrating oil stuff for a few days, and then with the spark plugs out, put the bike in top gear. If the engine is seized you will have to get the back wheel rocking backwards and forwards as you operate the gear lever in order to get the cogs to swap. If you don’t know where the gears are positioned, from neutral it is gear lever UP for bottom gear, then DOWN for middle gear,going thru’ neutral on the way, then DOWN again for top gear, or ‘High’ gear in Scott parlance. Once the bike is in top gear push it hard backwards and forwards, alternately, using the clutch to let you build up a bit of speed, (say walking pace). Hopefully this will free things up, unless the bike has suffered a severe seizure or other calamity.
If this doesn’t work you have a major problem on your hands, so let’s hope this is just a minor ‘rust in the bores’ nip-up.
Another dodge is to remove the kickstart pedal, noting that the big retaining nut is LEFT-HAND THREAD. You should then be able to see a one half inch square end to the layshaft, onto which you can slide one of the bits out of an impact-driver tool. You will then have a hexagonal hole facing you from the other end of the bit. If you have chosen the biggest size bit you can get a good-sized length of hex bar to fit into it, which can then be secured into the chuck of an industrial size slow-speed drill….. (There are variations on this theme using a socket wrench set and long tommy bars…..)
This can then have its trigger slowly tweaked, and should put more torque into the set-up than can be achieved by standing on the kickstart. Yet another tip before doing this is to drain the coolant out of the engine and radiator, and then fill it with boiling water straight from the kettle. Hopefully this may cause a bit of sudden metal expansion in the cylinders, that might help things along. PLEASE don’t do anything like belting metal rods down the spark plug holes, or levering thru’ the crankcase door openings, as this WILL break things ! Good luck.