NOt sure how to record my leg weights... help please?

Don't. At 2 1/2 pounds, they are only slightly over 1 kilogram. The general calculation for calorie burn is 1 Calorie per Kilogram of body weight per hour as the standard burn, so adding 1 kilogram to your weight while doing normal activities would only add one calorie per hour burn, or 24 extra calories per day burned. With the way BMR is calculated, it is easy to already have that much of a miscalculation depending on the formula used, so I wouldn't count it at all, personally.

OK so I should only count actual reps that I do not just having them on for normal activity? Also, there are 2 weights for a total of 5 pounds added body weight

Yeah, if you are using them for strength training then count them as strength training. If you are just wearing them while doing your normal daily activities, though, that's really only an additional 2.26 calories per hour while you have them on, or 54.4 calories per day if you wear them 24 hours. Most people won't wear them but 8-10 hours a day though, so only an extra 18-23 calories per day. Maybe add them if you are over by 20 calories on your eating?