help with windows form game

Question

i have created a game but it needs help, my code is really long (1000 lines). i asked around and people said that i could use methods but i do not know how to that, mainly becuase i do not want mess up my code but there are some errors in it and i could use some serious help.
the game is attached
update: i have made some serious modifications and cut the the code by 600 lines but i cannot find out why it is not working. I keep getting this error "identifier expected" i have no idea what the problem is.
if anyone could help i would appreciate it.
the source code is attached