It really is a pain in the @$%^!! to fix those things.
If you really good with small tools, have plenty of patience, you might be able to do it.
There are step-by-step Instructions on Ifixit.com.
I replaced the glass on our grandson's Ipod and it is a pain, the main thing is to the plug in, if you get it side ways you can ruin the plug and the unit will be useless, it helps to have very small hands also, and a lot of patience.
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If you aim at nothing, you will hit it every time!