How to convert sets of ODE to difference equations

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I have successful developed a continuous mathematical model for my physical system. The model comprises of sets of 7 nonlinear ODE. My objective is to transform the continuous-time ODE into a set of discrete-time difference equations and implement a digital controller for the system.

I will like to know the method/ technique for converting sets of ODE to discrete-time equations.

Example of the ODE is shown below.

$\frac{dT_1}{dt} = \frac{\frac{A(T_2 - T_1)}{M_1.C_v} + \frac{T_1}{M_1}.\frac{dM_1}{dt} }{1 + \frac{T_1.M_1}{vol.P}}$

$\frac{dT_2}{dt} = A(T_2 - T_1) + T_2^4$

$\frac{dM_1}{dt} = -A_v.\rho_{gas}.u$

$\frac{dV}{dt} = g.\rho_{air}.vol - M_1 - Drag$

$ \frac{dh}{dt} = V$

Thank you for your help.