Samsung Galaxy S4 Repairability Score: 8 out of 10 (10 is easiest to repair)

The battery can be replaced in seconds, without any tools.

Very easy to open and access internal components.

There are only 11 screws in the entire device, all standard Phillips #0 (no proprietary or security sizes).

Most of the smaller components are modular and can be replaced individually, but several of them are adhered in place, increasing replacement difficulty.

The glass is fused to both the display and the display frame, increasing repair costs.

You'll have to go through the entire phone in order to replace the front panel, since everything is built into the back of it.