Replacing seal on thresh hold.
 

The thresh holds are two level as in going from tile (raised) to garage floor (lower). The rubber seal is worn and starting to fray.

I thought it may be as simple as getting a replacement seal.....but now not sure of configuration/size....there are so many.

Replacing the entire thresh hold could be a bit more of a project.

Looking for tips/advice.

I would just pull it out and take it to Home Depot. If don't have the same size, go to Amazon.com. They sell just about anything. If you can't find a replacement seal, the threshold is not very difficult to replace. There are probably a few screws located under the seal. You just remove the screws and pry up the threshold, and screw another threshold down. You will probably need to trim the aluminum to fit the space.

There is an outside chance home warranty might have the name of the original manufacturer. If they do, you can contact the manufacturer to see if a replacement part is available. I have seen these both ways, replaceable and non-replaceable. The other option would be to carefully remove the as suggested above, take measurements, and so a search for similar items, and replace the entire unit. NOTE: having just done this the holes on the replacement unit will probably NOT line up with the old unit, so be prepared to drill holes (concrete) insert suitable plugs, and have suitable screws.

Hope this helps.

I just replaced 2 of mine,went to Lowes and asked for door bottom sweeps, they have the size and colors for doors we have in TV.
Pulled the pins from the hinges, laid the door down, removed the frayed sweep, the new sweep is just pressed on, replace door, done . Usually a 2 man job, when my son-in law was here we did all that and flipped the mattresses.

The threshold (not a "door sweep") is about 80% probably "Sluter" brand. Almost any floor covering store can supply it. A quick photo will go a long way towards explaining what you want. Also, in that situation asking for a "transition strip " may help get the correct product.