I have got a fixie wheel which i wish to change so i can use it on my road bike i want to also change it from 12-25 to 11-28 so it makes it easier on the hills, i have attached a image of the wheel i want to change
Not practical.
You are going to need a new hub, new spokes because most fixie/ss rear wheels are centered with the same length spokes on both sides, and freehub flanges are not centered - you may be able to salvage half the spokes, but not worth it at less than $1- each. You can probably re-use the rim - as long as your new hub has the same number of holes for spokes as your rim does.
Nigel
To use the same spokes on either side the hub flanges will need to be close to the same diameter as the old ones also. A new wheel is probably a better idea.
One other thought; you MIGHT be able to put a 7 speed 13-28 freewheel on the fixie hub; you'd probably have to add some space shims (precision washers) on the drive side, re-dish the wheel. And would only work if your road bike is 7 speed.
Nigel