Complex sentence: After killing a life, as pandavas procured Bramhahatyadosha (sin of killing), to get rid of it Bheema established a Shivalinga, followed by his brothers and Mother.
Split into simpler sentences: After killing a life, Bheema was burdened with Bramhahatyadosha (sin of killing). To get rid of it Bheema established a Shivalinga, followed by his brothers and Mother.