Ah here!
I'll be charitable and assume English isn't your first language.
Step 1: You look for another job
By one or more of the following steps
a. You contact recruitment agencies.
b. You answer job advertisements.
c. You update your LinkedIn / webpage / online profile
d. You contact people in your industry and / or network.
Step 2: You attend interviews
Step 3: You are offered a position & you accept it.
Step 4: You give notice to your current employer.
Step 5: You start your new job.