Re-potting acers

I have a large acer which has been in a pot since I bought it.   I think it needs re-potting and we have a large pot to put it in but it didn't do very well this year and I am wondering if it will tolerate being put in a bed in the garden after all its years in a pot.  We have a nice sheltered spot for it but I'm nervous because I love it and it was pretty expensive, so I'd hate to lose it.  Any thoughts?

As long as the area you've picked doesn't get waterlogged it should be absolutely fine. Prepare the area by digging out a hole twice the size of its pot and mix the soil with some good compost, plant at the height it was and, if it's large, give it a stake until it's had the chance to put down its roots.

Thanks very much.  I will do it today.