reaming sierra upright

[geeman]

well i just saw that i have to ream the sierra uprights at the bottom to allow the maxi ball joint to fit, but wondered what exactly needs to be done, as im not really very clear on what needs to be done in the hole at the bottom of the sierra upright.

Thanks

also i comletely fogot to buy the mushroom inserts, so where should i buy them from? also who do i contact at mk engineering for buying bits as there nothing roadster related on the site.