Here's an album I've used to replace my screen, (pictures are from the first link I've posted before) there are a couple of things to consider that aren't one these pictures nor any on the internet and don't make the sames mistakes I did. If you have pictures, and working screens from a different seller, please post it and I'll add it to the thread .
http://imgur.com/a/Rmy02
The tools I've used are screwdriver, a metal spudger, double-tape for cellphone repair, and a heat gun. And of course, your replacement screen. In my case I've purchased for 30 dol. on Aliexpress, but did not come with adhesive or tape so you have to have your own.
To remove the first section (4th picture), not only do you need to remove the cover and black and silver screws, but be careful because the center "rails" (the plastic parts to the sides of where the double sim and sd-card are) of the section are fixed to the battery section with "light" double tape, nothing too strong and can be lifted with care.
In the 5th picture, lift the white part of the connector and very carfeully to remove the ribbon. I've made the mistake to be too forceful and cracked the black part a litlle bit.
WARNING! THIS STEP IS THE MOST DIFFICULT, MANY PEOPLE BREAK THEIR BATTERY WHEN REMOVING, SO BE CAREFUL. AGAIN, YOU'VE BEEN WARNED
Now, one of the most difficult parts of the teardown is between 5th and 6th picture. After removing the uppers ribbon you have to take the battery compartment, and let me tell you that the white double-tape that glues the battery to the frame is one of the strongest i've ever encountered. A metal spudger can be helpful and you can start with pressing the left side, but don't separate too much or go too deep cause you might damage the envelope of the battery (I scrapped and exposed a litlle bit of the cells, but for the moment the phone works and don't heat. Just in case, I already ordered a new battery) . So be extra careful on this step.
In the 7th picture, things looks a little different of what I've found, the upper board has a metal protection that's soldered so DON'T TAKE IT OUT! Remove the upper left small ribbon very carefully. The cables on the down board that connects to the vibration motor are very fragile so be careful.
At this point, you can remove the speaker (I didn't) and you have the upper section, so the real hard work starts to be able to replace your screen. I'm sorry but i didn't take many pictures of this procedure, but again a metal spudger was helpful to be able to separate the cracked screen from the frame.
Remove all pieces of glue, glass or residue that's still on the frame and put the first part of the double-tape on the frame but don't take the upper part just yet. Take the replacement part and check it fits on the frame, paying atention to the two ribbons, one in the middle and other in the upper side. In my case, when I did put the screen I started with the upper ribbon and then guided the middle ribbon to it's hole and then fit the screen to the frame.
Make all the steps in backward order to be able to re-assemble the phone. The final optional step I did, is to seal the double-tape in the screen with the heat gun and some weight (I used a 2.5 drive and a couple of 3.5)
So in the end, I managed to replace the screen with only a couple of small mistakes. When my new battery arrives, the steps will be similar (I removed the white strong double tape with a light adhesive one, so it will be more easy to remove and replace the battery).
All in all, it went pretty well
LIST OF SELLERS WITH WORKING PARTS, according to users
AliExpress - Shenzhen OMG Trade co.,LTD - Screen For ZE551ML - USD 22.39 - gipikay (OP)
