I will typically create a duplicate layer, then use my regular tools (patch tool, healing brush, etc.) to completely remove the cracks and loose skin. Once that is complete, lower the opacity of the new layer until you reach a 'natural' looking result. When you're happy, either merge the layers, or create a new copy of the merged layers then use the dodge tool to add some shine back on top. Realize that you will lose sharpness, but that's pretty much the goal.
Hope that helps more than Sam's suggestion
