my parents were the same way, but im a year older. i just did it and the eventually found out, but the weren't mad because they new i couldn't reverse what i did. i would just take it apart at nite and do a couple quick mods.
Bradshaw- The long shot is simply not an easy gun to mod. Even the standard AR removal + spring addition isn't easily done. Spare yourself some frustration and listen to the older members of the site. Mod some other guns first. If you skrew up now it will cost you $30. A nite finder will cost you $6.