Another question about restoring metabolism

Okay, so I know there are a lot of posts about starvation mode and getting out of it, so I'll keep this brief.

I gain weight very easily. I struggle to maintain my weight eating 1500 calories a day and exercising for 30-40 minutes. I'm an 18 year old female. While I don't think my metabolism is too far out of whack, it is definitely a little slow from periods of undereating.

As far as restoring any damage goes, I know it will mean gaining a little weight and I'm fine with that...I could use to anyway. I just want to go about it in the best way.

So, my question is, do I jumpstart things by eating a lot of calories all at once? Do I increase in steady increments? Do I start eating the suggested maintence for my stats and let my weight increase gradually until I can successfully maintain at that calorie level? I just have no idea how to go about doing this!

Oh and when I plug in my stats in a teen nutrition calculator for someone who is lightly active I get that I should maintain on 1960, which sounds about right.

EDIT to add: I know these posts get frustrating and I don't want anyone to misread my intentions-- I know that I am at a low weight and I need to gain a few pounds anyway, I know that in order to increase my metabolism I need to eat more, and this will lead to weight gain. I'm FINE with all that. I just want to hear ideas on the best way to go about increasing calories! Thanks so much!

Chances are your metabolism is no different to anyone else's given the right conditions i.e. normal amounts of food, regular meals and a little exercise.  Go for the 2000 cals a day or however much it is that you need.  It's a not a major leap from 1500... Very simply plan your day so that you get 100 cals extra at each meal and 2 extra 100 cal snacks.  Slightly larger portions all around and a little more fat in your diet should do the trick

Don't weigh yourself for about a week to give your body chance to settle down and any fluid retention to come and go.  At 2000 cals a day, any weight-gain will only ever be temporary because it's a pretty low amount for an active teen.   If, after another week or two, you're still underweight... increase your intake by 500.  If you still don't gain, increase by another 500... and so forth.

I agree with gi-jane re: your metabolism. Metabolisms speed up just as easily as they slow down, once you're eating regularly and enough to support your activity level. I think you'll be pleasantly surprised that once you start eating more, your metabolism will adjust to cope with the increase.

Thanks for the replies guys. I'll try eating 1900-2000 calories (like gi-jane said, it's not too much more than I'm already eating) and see where that takes me.