What seats do you have? The factory lift out style take up the least room. And as you'll be able to see, there isn't much space to be promoted.
A smaller steering wheel might help, but might make the steering too heavy. Or you will need to look at more serious mods. Such as cutting the bulkhead and fitting seats that slide further back as per
@Turboman suggestion. But this is a one way mod that you can't undo and will only work on a hard top or full tilt, not a pickup and will prevent it ever being a pickup.
You could also look at moving the handbrake lever, but you'll have to R&D it a bit, And that is probably it. If you have door cards you can remove them to give a bit more knee room. But ultimately it you don't fit, the brutal reality might be, that it just isn't the vehicle for you.