Swansea take on League Two side Bradford in the cup final at Wembley on Sunday with the Welsh side looking for their first major trophy.
Rangel was part of the Swans side that won promotion to the Premier League with a play-off final triumph over Reading in 2011 and he hopes the players can once again deal with the emotions.
"I think you always have the pressure," Rangel told Sky Sports. "This time we are not the underdogs, we know that. At the end of the day, it's the cup final and it's all about emotions.
"Winning promotion from the Championship there was one of the highlights of my career. We are going back now and have the chance to experience it again.
"All we have to do is go to Wembley and perform. The most important thing is to win it. You don't want to go there and just play it.
"You just have to think what you would feel like if we went to Wembley and didn't win it. We would feel so bad.
"We know that if we don't win it, it will be a massive disappointment even though we have had a great competition. Let's hope we win it."
The winners of the game will compete in Europe next season which would mark a remarkable rise for Swansea - a process that has encompassed various managers.
The 30-year-old Spaniard credits everyone who has played their part but reserves special praise for current boss Michael Laudrup.
"He's a great manager," added Rangel. "He's a big name in football and knows the game very well. What he's done at Swansea is incredible.
"We also have to congratulate the four managers who have been here over the past six years. They've all played their part but obviously the most recent one will get the credit.
"We are in the top 10 of the Premier League and in a cup final so he deserves it 100 per cent."