Simple....
If you have any mechanical skills at all, then you should be able remove your pump and impeller.* You may need to purchase a special tool or two, but it's really not that hard.I'm curious as to what he meant by "loose"....?* Is it loose from moving it side to side, pushing from front to back, or rotating back and forth with a bit of slop.* The impeller is not tighten to the point it cannot be moved.* There should be a small amount of axial (in and out, back and forth...if that's a description) play but little or no radial play.* There may be a bit of play in the splines, but only a small bit.In removing the pump, there is only 4 bolts holding the pump on.* Four bolts holding the reverse bucket on and your linkages....then, if it's been off before, chances are it was sealed with silicone.* So, when you remove the bolts, you may have to wiggle it from side to side with some force to get it to pop off.......oh, and you have to remove the 1/2" cooling water pick-up hose from inside, near the transom where the pump is attached to the hull.I hope this helps.....I know there are posts in the forum that have more detailed descriptions than this, maybe do a search for more answers......Good luck!