How do I re-apply press-on flooring once its become loose?

http://www.diynetwork.com/how-to/rooms-and-spaces/floors/how-to-fix-curling-vinyl-floor-tile

You would need to add some type of adhesive tape or glue to stick them down again.

adhesive.... https://www.walmart.com/ip/Vinyl-Tile-Repair-Adhesive/38470675?wmlspartner=wlpa&selectedSellerId=1194&adid=22222222227026491962&wl0=&wl1=g&wl2=c&wl3=52579220591&wl4=aud-310687322322:pla-84460680551&wl5=9033057&wl6=&wl7=&wl8=&wl9=pla&wl10=112550058&wl11=online&wl12=38470675&wl13=&veh=sem put on with a serated edge trowel or just get the tape.

how to.... http://homeguides.sfgate.com/reset-loose-vinyl-floor-tiles-38593.html if the tile has curled, use a hair dryer to soften and flatten out

tape... https://www.amazon.com/dp/B0026SM9D0/ref=asc_df_B0026SM9D05155873/?tag=hyprod-20&creative=394997&creativeASIN=B0026SM9D0&linkCode=df0&hvadid=198062181806&hvpos=1o1&hvnetw=g&hvrand=18339382484526883486&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9033057&hvtargid=pla-321151332457

Not permanent tape.... use double-sided clear carpet tape.

just cover it with a cloth and re-iron it, then put a weight on it.

You need adhesive for vinyl and seam sealing kit. This is simple and instant fix. Then you lay a board or weight over it over night. If it curls or has been damaged from traffic before you reseal it, you may need a metal strip to put across the floor like they use to connect carpet and vinyl. Ask your hardware man for vinyl adhesive and seam sealing kit. If I can do it, anyone can! good luck

Susanland, IF there is any sticky backing left on it you could try heating the backing on the tile with a hairdryer and then try pressing it back into place until it cools off. If there just isn't any stickiness left and you have no extra tiles left to use as replacement (and don't want to find any for sale) I suppose you could just glue it down into place. WHICH glue? Perhaps the following link will help:

https://www.hunker.com/12003243/can-you-glue-down-peel-stick-tile

Thanks for using HOMETALK for answers :)

E-6000 should do the trick.

I would get some heavy duty construction adhesive and then put some heavy items on it to hold it down good.