Finance question with bonds

An investor owns a 1000 par value 10% bond with semiannual coupons. The
bond will mature at par at the end of 10 years. The investor decides that
an 8-year bond would be preferable. Current yield rates are 7% convertible
semiannually. The investor uses the proceeds from the sale of the 10% bond
to purchase a 6% bond with semiannual coupons, maturing at par at the end
of 8 years. Find the par value of the 8-year bond.

may want to use this resource https://archive.org/details/theoryofinterest00kell/page/1/mode/1up?view=theater