Yep, real pain in the ass the first time you try to reinstall the IBR bucket. Left side first, just start it and keep it loose, and then right farthest back next. Preinstall the bolt in the bucket mounting hole before you move it into position or like you said not enough room to insert bolt. I bought a set of angled ratcheting metric wrenches which makes things much easier after you get that back bolt started. Be very careful not to cross thread or overtighten any of the mounting bolts or you will be replacing both IBR mounting plates. Check torque values in service manual.