In the first step you need to hold the Holga and slide down the metal clamps on both sides and then remove the cover on the back.
You now have to remove the frame mask which should be in the camera.
You need to attach an opaque tape on the plastic runners which are located on both sides of the film exposure area. This is done in order to prevent or minimize scratches on the negatives.
Now adjust the take-up spool on the right side of the film compartment. Grab some rubber bands and wrap them around either end of the spool. This will give you a 1.35 inch slot right in the middle.
Now stick the film leader into the slot of the take-up spool. It is advised that you secure it with tape because it might slip from its place. It is recommended that you wrap the film around the spool such that the film is wound tightly.
The take-up spool now needs to be placed back into the compartment, which is the one on the right.
Take your two chunks of foam and place them in the top and bottom of the film compartment on the left. Wedge the roll of 35 mm film between the foam pieces. Make sure that the fit is firm and the film cannot move. It is important that your film should run across to the take-up compartment.
Now for some extra safety, you need to wedge a piece of cardboard under the take-up spool. You can get this piece by cutting it from the film box.
The count window, which is on the back of the Holga, needs to be completely covered with lots of tape. It needs to be remembered that a 35 mm film is not supported with paper backing and leaving the counter uncovered will only harm the roll because of the constant exposure to light.
Now you have to replace the back cover of the Holga and secure the metal clamps with tape.