If the dog has been crated all his life, it needs to be a slow transition out of the crate - and otherwise can be quite a shock for him. That's a major reason why I think training to NOT be in a crate should be started by about 4 months old (the crate is, after all, primarily a housetraining tool).
Still, just because he's a year old doesn't mean he's not perfectly capable of learning. It just means that it isn't going to be a normal, everyday, non-event for him as it would have been if it had been going on all his life. The way to train follows the same lines, whatever the age though.
He needs being loose in the house and on his own to be a non-event. Just a normal daily occurance that is not exciting, not frightening, doesn't mean he's abandoned - basically just a normal everyday occurance. And for that to happen in his mind, it needs to happen in reality

You can start training him in short periods. You leave the house, making a big show of your normal leaving routine (getting keys, coat, etc), and don't crate him before you leave. Of course, you're not really leaving - you're just going to sit outside your front door for 5 minutes. Then you return home - pay no attention to the dog, but just take off your coat, put your keys away - your usual hometime routine, minus paying any attention to the dog.
After 15 minutes, do it all again. And again. Try "leaving" for 10 minutes, for 15, for 30. Sometimes just for 5 minutes. So he can't guess, and gives up even bothering to look or guess how long you might be.
You need to do this over and over, for a period of days or even weeks. When he's paying absolutely no attention, try being gone for a couple of hours.
And when that works out OK, then try crating him in the morning when you go to work, come home at lunch, and don't crate him when you leave to go back (for some reason, they're usually more relaxed in the second half of the day). Keep that up for a little while, and then you're ready totry leaving him out all day.
For obvious reasons, dog-proofing wherever you leave him is a good idea. So is leaving him with a treat ball or other toy that has some mental stimulation attached to it. All day is plenty time for a dog to get bored
Do you see why I said it's easier if you start training them to be alone in the house and uncrated as young puppies though? It's easy for that to quickly become "normal" to them, and if it's never not been normal, then they're less likely to see it as a big deal when they're well enough housetrained for the crate not to be needed. It doesn't mean you can't train him now, of course. It just means that you need to go through that long desensitisation exercise first.