I like to get this tenis shoes white again how can I?
I would first throw them in the washer and wash hot. Then if they are not white enough, I would use OxyClean, let sit for a few minutes (10?) and wash again. I've done this with pillows.
Try 1 part water to 1/2 part Purex and soak shoes then was in HOT water with whites. See if that works. If you gotten grease or something like that on them then you are going to have to use a scrub brush and a degreaser first.
Clean the dirt off with old brush use white shoe polish works great.
Use a brush with whitening toothpaste and brush well, rinse with damp sponge.
Why not pop them in the washing machine?
Do any of the cleaning above and to avoid the yellowish while they dry wrap then with white toilet paper. The toilet paper will do the magic while drying.
Washer with oxy clean will come out like new.
I use a product called White Brite. It works better than anything else I’ve found. Also, take the lace out before you wash them and dry them in full sun.
I have found that using Purex or chlorox will allow the sneakers to develop a smell that I didn't like. I use BIZ BLEACH, it's colorsafe and it makes your whites even whiter. Before putting in the washer, I spray the shoes and the shoe strings with SHOUT and coat them really well. Put the Biz, a little of your detergent and dump the sneakers in the washing machine, adding a towel or two helps them wash better. I always dry mine in the hot sun on the hot sidewalk. They dry quicker and the sun helps them refresh themselves. I had a professional cleaning lady ask me how I kept all my linens and kitchen towels so white - it's because I use Biz and use the soak button on my washer. I have two great Grandsons that can really get their sneakers awful looking and this process works magic. You won't be sorry you tried it. A lot of people don't know about Biz Bleach but it's a must in my house and it's safe on colors.
When you are finished washing the shoes with any of the above methods that you choose, after they are thoroughly dried, be sure to spray them liberally with Scotchguard spray. This will greatly help protect them from and repel any potential stains.