Zoom XTECH HB100 Leak Fix with improvised bleed kit 

This is how I fixed my leaking brake from electric scooter.
If you want to do similar job, you are going to need some tools:
* T15 torx wrench
* T20 torx wrench
* 2mm hex wrench
* Small flat screwdriver
* Slip ring wrench or something pointy
* Mineral oil for bike brakes
* Bleed kit for hydraulic brakes (or you can improvise like me, see video)
* Needle nose pliers
* Replacement O-ring 7x2mm (ID, CS)