Swapping the oem 12cm housing, for a aftermarket 16cm housing.
Remove the air filter housing, and intake tube for access.
Remove the oil feed line at the top, and the 2 10mm bolts holding the oil drain at the bottom. Remove the large clamps on the intercooler tube and exhaust elbow. Remove the 4 bolts holding the turbo to the manifold, leaving one on loosely to prevent the turbo falling off too soon.
Notice how the inlet and outlet are situated, so that you may re-assemble properly.
Loosen the 4 bolts holding the exhaust housing to the center, only 2 of them can be removed at this stage. Hold the turbo up with the exhaust housing towards the bottom, and tap downwards with a hammer around the outer edge of the housing. You may need to soak it with penetrating oil. CAUTION, THE HOUSING MUST COME OFF STRAIGHT. Spin the impeller often, if it sticks, tap the housing back on where needed to straighten. Once it starts to come off, remove the other 2 bolts.
Now you'll see this;
The new housing will simply slide into place of the old one, again, it must be straight. Replace the 4 bolts, leaving them loose for minor adjustments later.
Re-install the turbo to the manifold, using new gaskets for the mating flange, and drain tube, and o-ring on the oil feed line (if needed)
You can now adjust the center section to align the oil return line, and intercooler tube.
Re-install intercooler clamp, and tighten everything, including the 4 housing bolts
You will probably now have this problem.
The exhaust elbow is too far away. Time for some exhaust "adjustments". You may be able to slide everything forward, or you may need to disassemble the entire exhaust system and re-install it.
'96 2500, CTD, 4X4 flatbed, Isspro gauges, Skyjacker D-25's, ThurenFab track bar, DSS, HD steering.
Motor; BHAF, #100 fuel plate, 5X.012 90hp injectors, Pacbrake 4kGSK, Loose starwheel. 306hp/743tq before injectors.
Exhaust; Schwitzer S300G, 4" downpipe, single 5" turnout stack.
Trans; Dunrite VB/TC, Intelligent Engineering billet input shaft, Burt Brown rebuild/upgrade.