Whats the best way to wash these pants?

Tech Specs:

Material:

[Shell] Polartec Power Shield Stretch Woven with Hardface technology 

Waterproof Rating:

Highly water-resistant 

Breathable Rating:

Highly breathable 

Fit:

Loose, 3-D ergonomic fit 

Side Zips:

No 

Venting:

No 

Pockets:

2 Front, 2 back, 1 cargo 

Seam Taped:

No 

Waist:

Belt loops 

Recommended Use:

Hiking, climbing, bouldering, backpacking, bushwhacking, anything 

Manufacturer Warranty:

Lifetime