I don't know what trouble you have but this really isn't the right place for this kind of question that will probably require multiple back and forth communications. Your best bet is to get on the Remington Society of America (a collector organization) forums and ask there.
http://www.remingtonsociety.com/forums
That is the complete. Model 12A It's the basic model.
Remington Works - 1914 (late)
Made 1915
1912
1912
1919
1919
You need a gunsmith
Ask a gunsmith for help
Early 1920
1918
You need to find a good gunsmith