Did one end of the trailer top drop? If yes, it may not have been two cables that broke, I could very possibly well have been the heavier master cable that ties the hydraulic ram lift yoke to the two corner lift cables. You need to get under the trailer to see what failed. If its a master cable, its pretty easy to fix because the entire cable is accessible from under the trailer.
More information is needed for more detailed help... like, what is the current position of the top? Up, down, cocked down on one end. What size trailer do you have? Small trailer tops can be lifted by hand (well strong hands attached to four or more strong bodies). Bigger rigs may need to be jacked.
If you are in an area with light industry, take the broken cable to a rigging repair shop... they should be able to make up a replacement cable. You can also get replacement cable sets from J & R Repair and/or Official Hi-Lo Parts. Both numbers can be found elsewhere in the HTF. Replacing a master cable, using a local cable source, shouldn't be an expensive fix. I had a master cable made up a month ago, to replace an old fraying one, and it cost $60. Took the tech about an hour to remove/install.
Better yet, if you can get the top down and have a reliable trailer repair shop in the area, drag it to them for repair. If you choose to do the work yourself, check the HTF Library, there is a detailed procedure on how to.
1967 17' Hi-Lo Bon Voyage (1967-1969)
1969 19' Hi-Lo Bon Voyage (1969-2011)
2004 27' Hi-Lo TowLite (2010-present)
2015 Chevy Tahoe LTZ