After going 69-93 and finishing in last for a second season in a row, the Marlins have plenty of work to do in order to improve in 2013.

The changes could start with the hiring of a new manager if owner Jeffrey Loria decides to fire Ozzie Guillen. Upgrades are necessary in most every area — hitting, pitching and fielding — and the road to recovery will likely require more than a quick roster fix that can be performed with a couple of minor tweaks.

Last year’s makeover has turned into a reconstruction project that began with the trading selloff in July.

So what went wrong — and right — in 2012?

What went wrong

1. Upper-level management — meaning everyone from Loria to the front office — grossly overestimated the team’s returning talent from the 2011 season. Did the Marlins overpay for free agents Jose Reyes, Mark Buehrle and Heath Bell during their December spending spree? Very likely, yes. High-dollar free agents are rarely bargains for any team. While Bell was a giant bust, Reyes and Buehrle performed pretty much to expectations. They can’t be faulted. It was the avalanche of failure of the existing bunch — everyone from Hanley Ramirez to John Buck to Gaby Sanchez to Josh Johnson to Logan Morrison, etc. — that brought down the house on the team’s “all-in” strategy.

2. Heath Bell. Guillen often made a point of saying that baseball isn’t like basketball, that two or three players don’t dictate a season. In Bell’s case, that idea was tested to the hilt. Bell not only drained spirit with blown save after blown save, but turned into a pariah figure among his own teammates with his constant finger pointing.

Many figured Carlos Zambrano would turn out to be the unpredictable fuse that would create an eruption. Instead, it was Bell, who tried too hard to be liked by every one. When Bell choked on July 8, blowing a 4-2 lead in the ninth at St. Louis the day before the All-Star break — the season was effectively over.

3. Hanley and Josh. Every team needs a superstar or two if they expect to contend. The Marlins banked on Ramirez and Johnson being the one-two hitting and pitching knockout punch that would get them back into the playoffs for the first time since 2003 when they won the World Series.

Ramirez, shoved to third base when the Marlins signed shortstop Jose Reyes, never got going. Johnson, an ace in the making when a shoulder injury cut short his 2011 season in May, was not the same, dominating pitcher in ’12 that the Marlins were counting on.

What went right

1. Giancarlo Stanton didn’t merely hit 37 home runs, the second-highest total in Marlins history. Stanton — who is all of 22 — crushed home runs that were ridiculous in distance. Stanton, not Milwaukee’s Ryan Braun, would have won the home run title had he played a full season. Stanton missed a chunk of it with knee issues.

2. May was marvelous. The Marlins set a franchise one-month record for wins with 21 to go with eight losses. The other five putrid months? 48-85. Abysmal.

3. Marlins Park. Eye-catching, to say the least. Though it was Death Valley for home run hitters, fans seemed to like the joint. The ballpark was worthy of high praise. The product on the field? Not so much.