How do I know what LED bulbs are safe to use in fixtures that are part of construction?
For interior recessed lighting, I don't think I've ever seen a can that wasn't rated for 60W or higher.  You can remove the bulb and the trim and look at the inside of the can for a sticker that lists the bulb wattage.  They normally do have labels.

That said, you have two options to update these.  You can get LED bulbs that are shaped like a standard light bulb if you want to keep your existing black trim.  You can also get LED bulbs that have an integrated trim (almost always a white trim).  To use these, you remove the current bulb and trim and replace with the LED module. They have a light bulb screw connector (Edison base) that screws into the existing housing to power the module.

Both the bulbs and the LED trim modules are made to work inside recessed cans, so the "MAX WATTAGE" label issue shouldn't matter here.



Random example light from SuperBrightLEDs