Test fit the terminals and the top 'hold down' bracket onto the top of the new battery with both outside the trunk, and do any necessary cleaning of terminals, mods etc, especially any necessary to make the bracket hold the battery securely,
BEFORE you start putting anything back into the frunk!
Then fit that bracket into its slots in the frame above & behind the battery and use some duct tape/100mph tape to tape it
AND the battery leads up out of the way before you try to fit the new battery into the hole. Once the new battery is in, it'll be easy enough to pull the tape off & drop the bracket into place on the top of the battery, then secure it, and fit the battery leads/terminals. :thumbup:
If you haven't already, don't forget to add star washers to the terminal nuts so that once tightened properly, they won't ever work loose again; and once it's all connected up again, just stick a socket on a long extension in behind the LH Wheel and make sure that the other end of the Earth Lead is firmly attached onto the end of the cable and tightened down onto a clean, rust-free section of the frame. That lead & the Earth it makes is essential to the proper operation of the DPS (electric Dynamic Power Steering) and the movement of the lead that invariably happens whenever you're removing/replacing the battery can loosen it/pull the cable out of its earth terminal fitting, resulting in either the DPS not working at all (Limp Mode results) or before Limp Mode kicks in, some
really hairy moments as the DPS cuts in and out while you're riding along &/or half-way thru a really tight corner with oncoming traffic!! :yikes: Do you really need to ask me how I know about that little heart stopper??

pps:
Oh, and
DO make sure that
YOU fully charge your new battery before installing it! Unless you
REALLY TRUST the battery retailer, it's best to believe that it
HASN'T been fully charged by them, and if you install it before
giving it a good 8 hours or so on a proper multi-stage battery charger (&
NOT just sticking it on a battery tender or cheap trickle charger!

) then make sure you practice and record everything you do while re-installing the 'new' battery this time around, cos without that good pre-installation charge, the chances are that you'll be replacing the battery
again a whole lot sooner than should be necessary!
So YOU should charge it properly FIRST! :lecturef_smilie:
Enjoy! :cheers: