At 59 with some extra pounds the problem was two fold, leather and fit. Discussing with an old world leather guy, he suggested sitting in butt first then swing both legs in. As an additional assist, I have a seat position set as far low and back as it will go and I use it on exit, thus entry. Works well and doesn't have you slide down the bolster.
While treating leather, I use Leatherique, don't forget the dash leather under the windshield and also invest in a good quality sun shade. Mine was damaged when I bought it and it was ugly. It dries like parchment in the sun and shrinks off the former making repairs very difficult.
As for seat covers, don't forget you have side impact air bags in the seats and the handbook warns specifically against any covers.
Hope this helps.