rear door hatch wont stay open what to do

The lift struts are in need of replacement. They can be sourced at any good auto parts store.

The hydraulic cylinder hinged are leaked and is need to be replaced

They are both correct. To remove them, you will need a torx for one end and the other end is a ball socket that is held together by a u-clip. Remove the clip to take it apart. NOTE: Make sure to safely prop the hatch open. They hurt if they fall.