So i sold my GTX 780ti. how do i use Direct X in software mode

i want to play KSP but its a little two much for the intergrated graphics. since its single threaded i can use the rest of the threads for software mode. but how would i enable software mode for direct X 9?

You don't, buy a new card.

i know i will im going to get a gtx 980ti. but. i just want to use software rendering so that its not slow.

but software rendering is slow...

i know but at least its better than intel graphics lol

What intel graphics? i mean my haswell i7 will run battlefield 4 with just the onboard, not much above 30FPS at 1080p on low but still.

First I would recommended reading a bit about Windows Advanced Rasterization Platform (WARP) - https://msdn.microsoft.com/en-us/library/windows/desktop/gg615082.aspx#how_to_use_warp

You have two way you can utilize it if the game developer doesn't support it:
1. Disable your integrated graphics driver and run on the Microsoft Basic Display Adapter which is (almost) guaranteed to work
2. http://gamedev.stackexchange.com/a/84522

Not that I would recommend this, but it may be worth a try