STEP 1 (draw the project) I take the meansures of berth on IKEA store, and with they i plan my modifications, ikea mydal is between kids and adult berth, i transform it for adult use only. we need made it higher, more width the entrance and new stairs to be confortable. Also we want a removable stair, to remove them by day, and use only by night. We have a very small spaces on this beach-house.
STEP 2 (Stairs)
They are the most complicated construction of the bed. I want to be removable stairs, to have more clean room by day. I use this method and it was easiest that i was thinking and it work great. You can also choice 2 different way to make steps, i use simply way, but i recomend you to be patient and try option A. One more thing, use a lot of wood glue :-)
I`m working on last instructions set, but i take more closed photo
STEP 3: Ikea Original structure is very small, i have heigh it around 20mm. And i have use recicled wood from structure. Finally, its, very important screw structure to walls, to have good stability. You can not heigh it withtout screw to walls because it will be very dangerous. The final result is a very stable structure, check photo for more details.