Unwieldy

adjective
difficult to use or handle or manage because of size or weight or shape
“we set about towing the unwieldy structure into the shelter”
Similar: unmanageable
adjective
lacking grace in movement or posture
“a gawky lad with long ungainly legs”
Similar: gawky, clumsy, clunky, ungainly
adjective
difficult to work or manipulate
“unwieldy rules and regulations”