Hi....
I'd remove the sparkplug and put some 2 cycle oil directly into the cylinder and leave it for a 24hrs.
Hope this helps.

Sometimes you can free up the piston with penetrating oil. Try to turn the crank in reverse, using whatever you need to do it. Sometimes this works.

Thanks. How would you turn it in reverse?

You could remove the head or maybe by just using a wooden dowel and hammer and with someone applying reverse force on the crank, gently tap the piston. Might take a few tries.

Sometimes they will move after cooling. There is probably some cylinder/piston scoring but it might run again.

I used penetrating oil and a hammer and dowel to get the piston moving. It's currently soaking in 2-cycle oil. I plan to rinse out that oil with the correct gas/oil mix and give it a try at starting. Wish me luck!

waiting

Sorry I didn't get back earlier on this. Much appreciation to everyone. I was able to free it up and it seems to be working the same as always. I just used a penetrating oil as suggested, tapping the cylinder lightly with a wooden dowel every day. It freed up in about a week.

Heh heh you didn't do it any favors but, you rescued it and it will do fine. Thanks for the follow up