You will need a copy of a source of any version of Spelunky. I'd recommend using TLS.
1. Run it in GM using Debug Mode (use the little red arrow instead of the green one on the bar at the top)
2. In the debug window you'll get, either click Tools --> Execute Code, or hit Ctrl-E.
3.
Copypaste in the following:
repeat(250){n = rand(1900) o = rand(1900) while(sprite_exists(n) == 0){n = rand(1900)} while(sprite_exists(o) == 0){o = rand(1900)} sprite_assign(n,o)}
making sure it's all in one line.
4. If you get an error, repeat.
5. Pteriforever is not responsible for the loss of any save data, sanity, or limbs as a result of using this piece of code.