For z expansion i Partially applied the excellent “Geonovast” modding.

Thingiverse link and detailed video tutorial here:

- Geonovast MPSM Z Axis expansion

- Video Tutorial

If 155 mm Z expansion is sufficient for you, then you can exactly apply Geonovast modding (except about z switch bracket, see further), otherwise you'll need to move extruder motor outside and change M4 Z leadscrew with a longer one (240 mm).

About extruder motor there is 2 placement option: first on alu angle like mine, or under upper chassis (this option require a longer PTFE tube), in all cases you'll need a 1,7 mm spacer and 4 x longer M3 32mm screws

About Rear chassis, because it interfere, "Geonovast" choosed to remove it, in my view it's a bad solution because of stiffness structure loss, so i kept it and just sawed parts that interfered (see picture 1)

Picture 1

i used the 35 mm support and motor spacer ("geonovast"), but not the z limit switch bracket 

1 - because my switch is bigger (than stock) 

2 - because i needed an adjustable z end stop system, in my view it's crucial !

i made my own with an electrical guitar small metal item and a screw, but it would be easier for you to design a new one (including a hot insert nut for ex) and print it.  here is some pictures of mine with comments, it could help. You'll have to do your own, good luck.