If the player has a high mechanic skill, he can sneak up on Kyle while he's sleeping (preferably after he passed out from being drunk) and rewire his watch trigger to explode when used. So, the next day when the player tells Bear to be defiant to Kyle and Kyle pressed the radio trigger, it explodes and blows off his lone good hand.
Combat Boy – All boils down to whether or not the player has put enough points into mechanic. If not, then a possible alternative is to get Jillian to rewire the trigger, provided the prisoner retrieval quests are done and the player didn't piss her off.
Diplomacy Boy – Same as Combat Boy, but player has the option to try and talk Sid into doing the deed.
Science Boy – Another shining moment for Science Boy. The skills are his, make good use of them.
Stealth Boy – This would help when sneaking up on the sleeping Kyle, but after that, it depends on how much was put into mechanics.
Edit