Steps for installing MSMC 6.0 without OST. Skip to step 3 if you already have SS installed.
1)Install SS 6.3
2)Patch to SS 6.4
3)Install MSC 6.0
4)Install MSC 5.0 to a separate folder
5)Patch this folder to MSC 5.0.3
6)Replace MSC 6.0 files with these files from 5.0.3:
Campaign_script.txt (\SS6.3\data\campaign\early\world\maps\campaign\imperial_campaign)
This file will be moved twice. Either from Early and Late, or TwoEarly and TwoLate, depending on if you want 1TPY or 2TPY. Note that the "early" folder in this directory varies depending on what options you want.
Descr_strat.txt (\SS6.3\data\campaign\early\world\maps\campaign\imperial_campaign)
This directory is exactly the same as above. Same deal, it will be moved twice, depending on which TPY mode you want.
Export_descr_buildings.txt (\SS6.3\data\campaign\early)
Again, move this twice based on your selection. The "early" part of the location once again varies.
Export_descr_ancillaries.txt (\SS6.3\data)
You're only gonna move this one once.
Export_descr_character_traits.txt (\SS6.3\data)
You're only gonna move this one once.
If you've followed these instructions properly, you should now be rid of OST.