I second Ian’s caution. I barely nicked the little rounded tab near the bottom of the cable and it rendered the touchscreen worthless. Had to buy a new (used) one.
I think it's the pics and the word 'slide' that throws people off. I tried this around 20 times to 'slide' it on from the left side, and was getting frustrated. My friend came over, laid the cover on the top, and just snapped it down into place. Still the guide had this down for me in 30 minutes even with the 'hardest part' haha and the part from ifixit worked and looked perfect.
I just used 1/4 polymide tape, and iFixit double sided tape. Works like a champ.
Suggest asking if they purchased a refurbished model. My last client's glass was held on with 30lb 3M shelf tape. No amount of heat or alcohol would remove it. Thank goodness the glass was already broken. I had to work for 2 hours to remove all of the glass, and old adhesive is not wanting to come off with elbow grease and alcohol. Going to try using tiny, careful amounts of goo-gone. Don't want anyone else to ever have to deal with this on future repairs (Client is a traveler, and accident prone)