26 inch wheels and fork on a 27.5+ frame
Overall its probably cheaper and certainly easier to sell the bike you have and buy the one you want. Building a bike from a 27.5 frame with 26 components you may end up with a bike geometry that is 'out' and handles worse than you already have. 

The new frame is likely a though axle, and may have a wider (Boost) spacing, meaning the rear hub will need adapters or replacing. The bottom bracket and seat post are unlikely to be compatible. You may need a new chain as the chain stay length could be longer.