changing stitches in a pattern

Hi, I was going to make a blanket from a Leisure Arts pattern called Kitten but instead of doing it on a size 4.5 and using 177 stitches I was going to use a 5.00 needle and I tried to cut down the stitches to 157 thinking that would work. I have done the 3inches in Seed Stitch but the pattern is not working out. The Row 1 is K1 (P1,K1) 7 times, place marker, K1 YO, K2 tog *K3, k2 tog, YO,K1,YO,SSK, K3,YO, K2 tog Repeat from * 10 times more, K1, place marker, (K1,P1) across to the last St and WYF slip1 as if to Purl
I have tried doing 6 on each end and have tried 5 on each end and thought I was counting the amount of pattern stitches as 13 but it’s not working out for me.
Any help would be great instead of me pulling out the Seed St that I began with

The pattern repeat is 13 as you thought and the pattern as given has 11 total repeats of that section. What if you work 10 repeats total which would give you 164 sts or 9 repeats which totals 151 sts?
You can likely work larger boders in seed to get to 157 if you go with the 9 repeats.
I can well understand not wanting to rip out the seed stitch you already have.

Thanks and that was the way I was thinking in the beginning but I am not sure what I am doing wrong right now that each change doesn’t seem to work for me I have had a rest from it now and will check it again as I thought it should work if I made the borders with K1,P1 6 times instead of the 7 and then it reads to K1 purlwise
I think I confuse myself. lol It was hard to try to add more stitches in the seed part so was trying in the pattern part. hope I make sense
thanks again!

The easiest thing may be to add stitch markers over the middle section of repeats. Then you’ll be able to judge how many sts are left for the borders.
That’s much easier than trying to knit and reknit row 1!

Thank you and that was what I did and finally got it together. Added a few stitches across and then did sets of 6 on the border. Thanks so much, it’s so nice to have someone to ask about these things!