At least OP didn't get the: "You need to post your location!!" scold.
![Roll eyes :rolleyes: :rolleyes:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
(Perhaps cold (is it frozen?), heat, humidity, sea salt corrosion, etc... effects the answer!!)
Even if the stabilizers are loose and should allow the sidearms
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
to swing free, a quick study shows they swing horizontally in a (slight) arc; whereas the sidearm needs to come off the attachment pin perpendicularly. This can be a problem.
Most of the time this arc is insignificant with light attachments that can wiggle on the ground. If sidearm can't swing along its arc it will bind on the attachment pin.
Sometimes the answer is a big hammer, or a swift kick, that moves the attachment (or the tractor) allowing the swing to continue.
Other times, with an attachment that is too heavy to "wiggle", having two people, one to very slightly move the tractor, unbinding the connection to the pin, as the other pulls, allows the swing to continue.
:2cents: