There is a modification that removes NotR: Gothic II Classic Mod
Description says it should work with the English version.
It's not exactly
the same, but very similar. Haven't tried it myself.
According to the description, there are following differences between the "real" classic version, and this mod:
-) You can do the Novice quest in Chapter 2, which was not possible
-) several exploits and bugs were fixed
-) There are new ways to defeat the final boss (I'll keep this one vague, so not to spoil anyone)
-) What they kept from the add-on, is that it is harder to climb the city walls
-) There are also some visual effects retained from NotR, magic spells for example
-) They're not sure if there are differences between Classic and the Add-on regarding textures, music and the fighting AI of the monsters. If there are, they're also in this mod.
-) With 1.1 you now get 30% of the price with merchants, as it was in the original (in NotR it's only 15%)
-) They've also reimplemented the possibility to finish the game without joining a guild