Pretty much the same rules as making any SU model smaller. If it's a repetitive model you can turn geometry into instances of eachother. It depends entirely on what's making the file size so big though. Maybe you can post a screenshot of the model. -Brodie

Does this help http://forums.sketchucation.com/viewtopic.php?f=79&t=39940 ?

Hi, You can replace a button on a chesterfield sofa by removing the old button-through pulling. Discard it and make a knot of twine on a metal pin. Adjust it on the twine needle and insert it into the sofa. Rotate counterclockwise and remove the twine needle. Install the new button and make knots.

Thank you, for the quick reply. No more blobs.