I don't know where you live or the part of the country you're in, but I am assuming you are in the US... I would recommend finding a reputable local dealer to do this for you rather than send it off. It will take less time and if there is any issue it can be handled locally.
Most cities over 25k people usually have a few places that do this, as do many chains like Batteries Plus, Office Depot/Max, and Staples (some locations do same day in-house repair, some ship out), there are often mall kiosks that can do this same day as well, although most of these places won't likely stock a screen for the MXPE and will have to order it first. A little research, Google, and your local on-line classifieds can often be of help here.
TBH though, for the LCD and digitizer assembly (they need to be replaced together) the wholesale cost is $50-$75, add markup and labor you are likely pushing $150+ for the repair as replacing the screen on this device is not a simple task. A new devices runs well under $300, with Best Buy, Newegg, and B&H often running them for $250 or less on sale. It might make more sense to replace it depending on the cost of the repair.
One word of advice, get a firm quote on the cost before agreeing to it being done, this repair is not simple on this device, and a dealer may well try to increase the cost after the fact if they are not familiar with the difficulty in doing the work on this device. Also be aware that your waterproofing will likely be gone too, although that might not be a real issue to most people.
