I haven't done one but looking in the manual it says,
"NOTICE
The differential gear assembly is assembled
into a proper unit at the factory by means of
specialized equipment. Do not attempt to
disassemble this unit. Disassembly will result
in the malfunction of the unit."
It also says,
"Do not disassemble the differential motor or
remove the differential motor pinion gear.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect two C-size batteries to the differential
motor terminals “1” (as shown in the illustrations).
NOTICE
• Do not use a 12 V battery to operate the differential
motor pinion gear.
• Do not connect the batteries to the differential
motor when it is installed in the differential
case.
• The differential motor should be checked
when it is removed from the differential
case."
Then it doesn't actually say how to remove the servo motor, but to assemble it it says this,
"• Differential motor
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Slide the shift fork sliding gear “1”, which is installed
to the differential case cover, to the
right front constant velocity shaft assembly
side as shown in the illustration to put it into
the 2WD mode.
b. Connect two C-size batteries to the differential
motor terminal “2” to operate the differential
motor pinion gear “3”. Operate the
differential motor pinion gear until the mark
“a” on the differential motor pinion gear is
aligned with the mark “b” on the differential
motor case.
NOTICE
Do not use a 12 V battery to operate the differential
motor pinion gear."
Not sure if you reverse the above you may be able to remove the servo motor? Hope that helps.
"NOTICE
The differential gear assembly is assembled
into a proper unit at the factory by means of
specialized equipment. Do not attempt to
disassemble this unit. Disassembly will result
in the malfunction of the unit."
It also says,
"Do not disassemble the differential motor or
remove the differential motor pinion gear.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect two C-size batteries to the differential
motor terminals “1” (as shown in the illustrations).
NOTICE
• Do not use a 12 V battery to operate the differential
motor pinion gear.
• Do not connect the batteries to the differential
motor when it is installed in the differential
case.
• The differential motor should be checked
when it is removed from the differential
case."
Then it doesn't actually say how to remove the servo motor, but to assemble it it says this,
"• Differential motor
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Slide the shift fork sliding gear “1”, which is installed
to the differential case cover, to the
right front constant velocity shaft assembly
side as shown in the illustration to put it into
the 2WD mode.
b. Connect two C-size batteries to the differential
motor terminal “2” to operate the differential
motor pinion gear “3”. Operate the
differential motor pinion gear until the mark
“a” on the differential motor pinion gear is
aligned with the mark “b” on the differential
motor case.
NOTICE
Do not use a 12 V battery to operate the differential
motor pinion gear."
Not sure if you reverse the above you may be able to remove the servo motor? Hope that helps.