How to change creative to survival on Minecraft PE?

I have Minecraft PE on IPhone 4. I've built a house on creative and I want to change to survival. I've looked it up but I can't find any of the apps they say I need. Im desperate! Please help!

Wrong category

First off you need your iPhone to be jail broken.
After that download iFile from Cydia and go into the "minecraftworlds" folder, copy the chunks.dat file of the creative world, and paste the chunks over your survival world. (It will say overwrite click on it) And your done! (: Oh btw, animals and signs won't be copied over for some reason:/ Contact me if you need simpler instructions: D

How t
Do I jail break