The easy way to hatch eggs is with a hen. You'll need a broody hen, a safe nesting box, and patience. When they hatch you'll need to house the chicks in a brooder box to protect the hatchlings from both cold and predation. It all sounds very straight forward, but to hatch out chicks the conditions have to be right. Welsummer hens are non-sitters for the most part, and some broody hens will not accept eggs from other breeds.
Many hens show definite preference in selecting eggs to hatch based on size and color.
I've even seen nests cleared of eggs that did not match those belonging to a specific breed. My experience has been that the more feral in nature the breed, the more pronounced this selectivity. Welsummer eggs are much darker than most other eggs. This and the textured speckling on the surface of the eggs easily differentiates them from the eggs of other breeds. Good broody hens, however will accept a mixture of egg varieties.