Basically, the idea is to rotate your axes so that the given curve is a hyperbola in the usual sense. In order to do this, we let
$$x=X\cos \theta+Y\sin\theta \; \; \; \; \; \; \; \; \; \; \; \; \; y=-X\sin\theta+Y\cos\theta$$
where $(X,Y)$ are the coordinates in the rotated axes.
For ease of notation, I shall define
$$c=\cos\theta \; \; \; \; \; \; \; \; \; \; \; \; \; s = \sin\theta$$
Plugging this in, we get
$$(Ac^2-Bsc)X^2+(2Asc+Bc^2-Bs^2)XY+(As^2+Bsc)Y^2+(Dc-Es)X+(Ds+Ec)Y=-F$$
With a hyperbola, we want to make sure that the $XY$ term disappears. i.e., we want to choose $\theta$ such that the coefficient of $XY$, which is $2Asc+Bc^2-Bs^2$, is $0$.
\begin{align}
\ & 2Asc+Bc^2-Bs^2=0 \\
\ \implies & A\sin(2\theta)+B\cos(2\theta)=0 \\
\ \implies & \theta=-\frac 12 \tan^{-1} \frac BA
\end{align}
With this particular value of $\theta$, you work out what $\sin \theta$ and $\cos \theta$ are, and plug them back into the equation above to get something in the from of
$$PX^2+QY^2+RX+SY=-F$$
which implies that
$$P \biggl(X+\frac{R}{2P} \biggr)^2-Q \biggl(Y+\frac{S}{2Q} \biggr)^2=\frac{R^2}{4P}+\frac{S^2}{4Q}-F$$
where $P,Q$ should be positive.
Then, via a shift in the axes and some rearrangements, we get the required hyperbola.
Probably easier to understand with an example.
Say we have the equation
$$x^2-\sqrt 3xy+\sqrt 3x+y-\frac 73=0$$
Then as before, we let
$$x=X\cos \theta+Y\sin\theta \; \; \; \; \; \; \; \; \; \; \; \; \; y=-X\sin\theta+Y\cos\theta$$
$$c=\cos\theta \; \; \; \; \; \; \; \; \; \; \; \; \; s = \sin\theta$$
Plug this in to get
$$(c^2+\sqrt 3sc)X^2+(2sc-\sqrt 3c^2+\sqrt 3s^2)XY+(s^2 - \sqrt 3sc)Y^2+(\sqrt 3c-s)X+(\sqrt 3s+c)Y=\frac 73$$
We want to chose $\theta$ such that $2sc-\sqrt 3c^2+\sqrt 3s^2=0$, so
\begin{align}
\ & 2sc-\sqrt 3c^2+\sqrt 3s^2=0 \\
\ \implies & \sin (2\theta)- \sqrt 3 \cos (2\theta)=0 \\
\ \implies & 2\theta = \frac \pi 3\\
\ \implies & \theta = \frac \pi 6
\end{align}
If $\theta = \frac \pi 6$ then $\cos \theta = \frac{\sqrt 3}{2}$ and $\sin\theta = \frac 12$, so
$$\biggl(\frac 34+\frac 34 \biggr)X^2+\biggl(\frac 14 - \frac 34 \biggr)Y^2+\biggl(\frac 32 -\frac 12 \biggr)X+ \biggl(\frac{\sqrt 3}{2}+\frac{\sqrt 3}{2} \biggr)Y=\frac 73$$
$$\frac 32 X^2- \frac 12 Y^2+X+\sqrt 3 Y=\frac 73$$
$$\frac 32 \biggl(X+\frac 13 \biggr)^2- \frac 12 \bigl(Y-\sqrt 3 \bigr)^2=1$$
And hence
$$\frac{\hat X ^2}{(\sqrt {2/3})^2}- \frac{\hat Y ^2}{(\sqrt 2)^2}=1$$
where $\hat X = X+\frac 13$ and $\hat Y = Y-\sqrt 3$