How did Trunks beat Freeza?

[Neo-Makaiōshin]

By being stronger, simple as that. And probably knowing something about anatomy to perfectly cut Freeza in pieces, effectively.

[Son Perfect]

Speaking context wise, Toriyama played up Trunks to be leagues above Frieza to make the reveal of the artificial humans terrifying. In reality, no one really knows how strong Trunks is compared to Frieza and even Goku at the time. Frieza is "nothing" to Trunks and Trunks is nothing to the artifical humans.

[lancerman]

Since Freeza can use anywhere from 1% to 100% of his full power in his final form, it's impossible to know. He definitely wasn't 100% because we know that looks different. We also know that Freeza does have to power up a bit to get to 50%. So it's highly likely Trunks got there sub 50%, which a SSJ should be able to wreck.

[rereboy]

Trunks was just stronger. The sword and Freeza probably not being at 100%, made things easier for Trunks, but Trunks would still win, it would just take longer. The whole point of Trunks giving the sword to Cold was to point out that the sword wasn't the reason why he won.

[Akyon]

Frieza let his guard down, he was overconfident but also still terrified of the Super Saiyans at this point, his body whilst RIDICULOUSLY tough seems to be weak to bladed edges(see Krillin's Kienzan being the only permenant damage on Frieza for ages) and Trunks is the only Super Saiyan who doesn't turn into a "I'm going to prolong his suffering to showboat how powerful I am" moron.

[Ssjcell]

Did you not watch the fight trunks was much much stronger than frieza...