Make an official request with child support enforcement. see links
Termination of parental rights does not terminate one's child support obligation.
Relinquishing one's parental rights does not terminate one's child support obligation.
I suggest you consult with the other parent and an attorney on this. However, keep in mind that terminating parental rights does not terminate one's support obligation.
Signing over one's parental rights does not does not terminate child support.
The parents are liable for support to the State, unless/until the child is adopted. Losing one's parental rights does not terminate one's legal responsibility.
One way is if the child is adopted by someone else who is willing to become responsible for supporting the child. Otherwise you need to petition the court to modify or terminate the child support order.
Courts do not generally allow a parent to terminate parental rights unless there is another adult waiting to adopt the child. You need to add more detail to your question since you have suggested an unusual arrangement where you terminate your rights yet still pay child support. You should consult with an attorney. If you plan to continue to pay child support one wonders why you want to terminate your parental rights.
Possibly, if the parent still receiving support files for modification based on your financial change in circumstances.
Child support is set by order and is based generally on net income. Job Corps does not automatically terminate one's support obligation. But, you may need to get an adjustment. see links below
If you have owed it up to that point and haven't paid it, more than likely.
Yes you can sign over your rights to the one child and not the others. However on child support you will not have to pay on the one you signed off on but as for the others that you claim yes you will pay. In general, parental rights are terminated either preparatory to an adoption, or after a trial in which it is determined that the parent is unfit. In any case, termination of parental rights does not, in itself, terminate child support.
Signing over one's parental rights does not terminate one's child support obligation.