You'll want to start your pony as if you were training her to ride. Do the join-up game, and then basic lead-line exercizes. A round pen is best, but any modestly sized enclosure will work.
This really shouldn't take much work, but you may need to repeat the lead-line bits periodically.
There are plenty of sources for info on these training techniques, as they are a common denominator in nearly all equine training. You should be able to find what you need on-line, but it will probably be beneficial if you find someone to work with you the first time thru.
Hope this helps. Steve
Steve Jernigan KG0MB
University of Colorado