Answer
$a_g = \frac{0.2495~c^4}{G~M_h}$
Work Step by Step
$R_h = \frac{2GM_h}{c^2}$
We can find $a_g$ at $1.001~R_h$:
$a_g = \frac{GM_h}{(1.001~R_h)^2}$
$a_g = \frac{GM_h}{(1.002001)(\frac{2GM_h}{c^2})^2}$
$a_g = \frac{GM_h~c^4}{(1.002001)(4G^2M_h^2}$
$a_g = \frac{c^4}{4.008004~G~M_h}$
$a_g = \frac{0.2495~c^4}{G~M_h}$
