Depends on the kind of riding you do. For dirt stunt pegs are just in the way. For grinds and flatland tricks they're required.
If it has nutted axles - probably. If it has quick-release skewers - no.
Yes U CAn But U have 2 replace the nuts!
Only if you're planning to use them.
yes u can
top
The left side
Yes, pegs can be put on any BMX Bike. You will need a socket wrench to put pegs on certain bikes how ever.
You can see DIY Bike Repair Videos below.
buy a longer axle and put bearings on one side of the axle
axle mounted, yes.
I'm assuming you're talking about an BMX here... Undo axle nuts, put pegs on. With an extender and a socket wrench, get the axle nuts back on and crank down.
Depends on that you mean by use. To put them on all you need is for the bike to have a place where they can bolt on. But whether you'll be able to do something worthwile with them or not is another question.
No.
It is not very hard to put full downhill on a normal mountain bike but you need to take it to a professional.
Unfortuanitly not. Not unless you have the right kind of axles. Also to legally use pegs you need to be able to do a bunny hop and three sixty, and send a video of you doing it to the UBA ( united biking academy ) I learned that the hard way :(
Unbolt wheel nuts, put on pegs in their place using an extender and a socket wrench.