Replacing a vob with a different vob

[Titan6]

How would I be able to change vob file named 12_1.vob(movie extras) with vob file named 2_1.vob(extras from different movie). I've manaually changing vob and ifo (ie 2_1.vob into 12_1.vob) but it wont work. Could any help?
12_1.vob is 2ch 100mb
2_1.vob is 6ch 800mb

[oddyseus]

I am afraid that u can't just replace a file with another and hope to work.

vob files contain pgcs/cells inside. U have to match each others pgcs in number and placement for the switch to work out.

ie, lets suppose that your original vob has 5 pgcs each pgc having 1 cell inside. U can replace it with another vob file having exactly the same structue but not any other. In the later case u will be able to burn but when it comes to playback u ll be dissapointed.