Emigration:

After adhesion of leukocytes, they insert their pseudopods into inter-endothelial gaps.

They squeeze through these gaps and occupy a position between endothelial cell and basement membrane.

Finally, they crawl through basement membrane and escape into extravascular space. This process by which leukocytes comes into extravascular space is called emigration. It is also known as transmigration and diapedesis.