Is it possible to get creases (as in trouser leg creases) out of permanent-press clothes?
Oh, without wrecking them of course. 
I understand that those creases are put in originally by heat—but a much higher heat than that in your clothes dryer. Get the pants hot enough (without catching on fire) and the creases will come out.
I vaguely remember years ago when the thermostat stuck on my clothes dryer and superheated some permanent press pants----lost the crease.
I no longer remember at what temperature permanent press creases were put in. (Used to do laundry repair and at one time knew all that stuff).
Anyway if you equal or exceed that temperature then permanent press creases will disappear.
All I remember from personal experience was that when my dryer’s thermostat stuck closed, the air temperature and clothes inside were then cycling on the safety high limit switch—as I remember right preset at about 220 degrees (or a little less than 100 degrees over the operating thermostat cycling temps).
And my permanent press pants did lose their “permanent” crease at that temperature without catching on fire.
Why would you want to take the crease out of your pants?
Anyway —the solution to removing those creases is to --Jumper the operating thermostat in your clothes dryer, let the dryer cycle on just the high limit safety switch-----for maybe a 1/2 hour or so–
(And stand by with water just in case of fire)
I bought a pair of nice trousers for my teenage son, but he is a veritable slob and decided he didn’t like the ‘formal’ look (bieng more used to wearing tatty jeans). So I figured that if the crease were gone, he’d be more likely to wear them.
But as some of your methods sound a bit dangerous and drastic disponibilite, I think I’ll just leave them alone. NO trousers are worth modifying the dryer AND having to chuck a bucket of water over when it does a major fritz-out 
Thanks for the advice though.
You might try a steam iron set high, at cotton or maybe linen, while paying attention.
I tried this very thing this morning with my husbands permant creased pants and it didn’t work.
I’m just going to have to continue to press his pants along their incorrect line.
I’ve found, in my younger days in high school and pleated grey uniform shirt, that I used waxed paper between the pleats from underneath, it seemed to hold the creases in longer without a permanent problem, in case I made an error in lining a pleat up. Waxed paper is cheap and readily available and certainly saves you the problem of paying someone else to make a mistake that can’t be reversed.
Easy fix. Take it to the dry cleaners and have them press them. My mother used to do this.