this is a super basic safe
Step 1: Cutting the Candle
take thin wire and put the candle in a vice grip then cut the top off by pulling the wire back and forth until the top comes off.
Step 2: Cleaning
take your knife And scrape out the inside of the bottom of the candle and light the inside wick to help melt it, when you finish smooth off the sides.
Step 3: Fitting the Top
scrape the top at an angle \ so it will fit on the bottom piece then take part of the wax scrapings and put them in the gap and melt them in and smooth it out,
Step 4: Fin
take a razor and recut the wax so the top is easily removed and your done