Of course you can train them. Not the easiest dog, but likely not the hardest, either. Many methods will work, but consistency is key. Clicker training is great for quickly teaching new behaviours, but I think is misunderstood. You use a clicker to indicate what you want, you teach the behaviour incrementally until you reach your goal, and once it is consistently being given and rewarded, you name it (put it on cue). You should also "generalize" the behaviour....dogs do not necessarily understand that something taught in one place can also be requested somewhere else. Once a behaviour is on cue, you do not use a clicker when you ask for it, and you should reward intermittently, not every time. (there is a reason casinos give little rewards from time to time, keeps people.....and dogs....trying to earn one!)
To give an example, my first venture into clicker training with my Perry was to go into his crate on command. I started in a small room with the crate present, clicked and rewarded for any time he approached the crate, incrementally rewarding only for a closer approach, finally for front feet in, then whole dog in, then consistency and put on cue. Total time taken: 15 minutes. We generalized so I could say "kennel" from another room and he would go there. (this is a dog who hates crates, so I was careful never to close the door on him!). I similarly taught "pick it up" by rewarding close to object, nose near object, touching object, opening mouth near object, finally he figured it out and I put it on cue.
I taught my horses to use a nose push activated automatic waterer the same way!
Sorry, this is getting a bit long, but I wanted to be clear about clicker training. And you don't actually need a clicker, you can use a marker word ("yes!" is a common one), but the clicker gives no intonation and is always the same sound, so possibly a clearer signal. "Positive" trainers use a lot of different approaches, e.g. luring the dog into the behaviour with food, or waiting for the behaviour to present (the dog sits down, the trainer clicks the behaviour) etc. Or you could just go "old school" and the dog will learn that way too, but it won't be politically correct these days.