Please I need help designing a 4way speaker crossover Network

Here's the problem.. The cross-over network will cause degradation of the original signal..
I assume you want a passive cross-over, in which case this will certainly be more likely.
In order to use an active cross-over, you will need amplifiers which could be prone to noise if not constructed properly.

You are going to need the following circuits wired in parallel:
Low-Pass filter
2x Band-Pass filters
High-Pass filter

You will need inductors and capacitors to attenuate the higher and lower frequencies to reduce the size of the unwanted signal from reaching the speaker.
Do you know what frequencies you want to pass or attenuate for each speaker? You can find all sorts of resources to help determine component values once you have this.

 

https://trueaudio.com/st_xov_1.htm
There are a number of calculators of various order filters on line

 

BING search for "Low pass filter tutorial" returns result:
http://www.electronics-tutorials.ws/filter/filter_2.html
You could do similar search on other key words.
2x Band-Pass filters tutorial
High-Pass filter tutorial