One of the causes for bulky uterus is that it would not have shrunk back to the original size after child birth. During the pregnancyit would have expanded and it supposed to shrink back to the original size later.
Certain yoga exercises could help you in shrinking of uterus. One of the effects of large uterus will be heavy bleeding during the periods. This could be very dangerous over a long period of time. Heavy bleeding during periods could make you anemic and being anemic will increase the bleeding further. So this is a cumulative problem.
Other than exercises, one other solution is having the uterus removed. This is possible if you are around 40 years and you do not plan to have any more children. If so you can get the uterus removed through vaginal extraction. This is a painless operation and there is no need for the abdominal cut. In this type of operation the blood loss is very minimal and you can be back to routine activities in 2 weeks (including going to work, driving, walking and doing most of the house work - except lifting heavy objects for a while).
Also if the ovaries are not affected in any way, they will not be removed and hence your harmone generation is not affected.
Best thing is to consult a GYN/OBJ doctor and take it further from there.