I have this bump on my skin filled with blood and it's been there a while. how do i get rid of it?

See doctor: A blood filled sac could be hematoma which can be drained . However it may be deeper and before opening the lesion an ultrasound or scan may be necessary to determine the depth. If it very deep it may need to be treated in hospital or outpatient surgery center. Since it is been there for a while it will not resolve without medical attention.

Blood filled bump?: I suspect that you are most likely referring not to a hematoma, but more likely a small hemangioma. These often appear as we age, are often multiple and are ususally red to purple. There are also venous lakes, most often on the lip, which are small vericose veins. All of what I have described may be treated with lasers.