Fully ready to rebuild the pier (4)
I believe the answer is:
ripe
'fully ready' is the definition.
(I've seen this in another clue)
'rebuild the pier' is the wordplay.
'rebuild' indicates anagramming the letters (I've seen this in other clues).
'pier' anagrammed gives 'RIPE'.
'to' is the link.
(Other definitions for ripe that I've seen before include "Mature, ready to eat" , "Ready for harvesting, in its prime" , "Right" , "Fully developed, ready to be eaten" , "Mature, fully grown" .)