if the espalier shape is in relatively good condition (meaning the majority of the tree is growing out horizontally and not vertically) and you already have the wires/stakes in, simple maintenance is easy enough to do on your own.  I recommend looking up Monty Don/Gardeners' World videos on how to train and maintain espalier trees.  It is a UK gardening program and they have a very helpful website but also many video clips on You Tube.  The key thing to remember is that cuts in summer (too late this year) will stunt growth, and cuts in winter (too early right now) will likely stimulate it.  So if a branch is not properly trained and growing up, the best time to tackle may be in the summer.  Good luck!