The cheapest route is to replace just the lamp. For example, if you currently use BR40 lamps,
http://www.homedepot.com/Electrical-Light-Bulbs-LED-Light-Bulbs/h_d1/N-5yc1vZbm79/R-202670532/h_d2/ProductDisplay?catalogId=10053&langId=-1&storeId=10051

Philips also has a Led BR40.

The housing does not have to be replaced.

The only significant difference between a standard incandescent can and a led equivalent will typically be the connector.

Thanks for the suggestion. But I see I left out some pertinent information. The old lights have the eyeball trim and we wanted to replace that with the plain trim. That is why the retrofit kits seemed like the ideal solution, sort of a two for one. An electrician told us we couldn't just go from the eyeball trim to plain trim without changing out the housings too, because of the way the socket was inside the can. So I do not think just changing the bulbs is feasible.

That's interesting if your existing lights use standard A19 incandescent bulbs.

The next option would be to use 6" retrofit cans and the ECO-575 (CR 6).

The holes will be enlarged.

That's interesting if your existing lights use standard A19 incandescent bulbs.
The next option would be to use 6" retrofit cans and the ECO-575 (CR 6).
The holes will be enlarged.

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David, again, thank you so much for your help. We are really novices when it comes to lighting and your help is invaluable.

I just wanted to make sure that I understood what you are recommending. Are you saying that if we wanted to get new trim with our non-standard size housings, that our best option would be to replace the current cans by enlarging the ceiling holes that are presently in the ceiling for our current units, install new 6" retrofit cans with a standard Edison base, and then buy (Cree) ECO-575 retrofit LED kits for each new can?

Options
1. Re-use the existing cans. The eyeball trim is typically a separate replaceable piece. From your earlier descriptions, it appears that the light fixtures use A19 type bulbs with the screw in base (Edison). It might be possible to get trim pieces + bulb. That way, you save on the labor required to remove and re-install cans.

2. Replace the can. If you have access to the upper side, removing the can should be relatively easy (though not necessarily pleasant). Otherwise, a large portion of the can should be removable from below. In this case, enlarging the hole is less work than attempting to shrink the hole.
Assuming that you are not subject to energy efficiency laws such as Title 24, standard edison base retrofit cans are usable.
You may want to use the ECO-575.

What did you finally decide to do? I'm in the same situation with cans measuring 4.75" labeled "Prescolite." Replacing them with standard cans go way beyond my skill and patience level.

Don

Prescolite is a brand owned by Hubbell lighting. You might be able to find a suitable drop in replacement from the link below

Prescolite LED link

I had the same problem. For anyone running across this ancient thread, here is an imgur album of my solution:

https://imgur.com/gallery/PWwVxkq