This should work on any one xl using stock deodexed sense but has only been tested on the att version.
First off you must be rooted and have a deodexed rom installed.
You will need some type of file explorer I use root explorer
You will need this app Zip Themer installed on your phone LINK
Once you have Zip Themer installed grab the attached file and place it in the folder on your sd card named zip themer.
Whats inside the zip? It is a compiled status_bar.xml with the center clock mod applied.
Now run zip themer select +theme and then select the zip you just placed in the folder then select build it when complete you will find two zip files on the root of your sd one called update and one called undo take the the one name update and unzip it inside you will find a systemui.apk.
Take the apk and navigate to system app folder and create a folder name temp.
Place the apk inside now fix the permissions to match the existing systemui.apk
Once you have done that move it to the system app folder it will ask you if you wish to overwrite the current apk say yes and reboot phone and you will have your clock centered.
If something goes wrong the undo folder contains a original copy of your systemui.apk so can replace it.
Now if your feeling more adventurous and wish to change out some icons as well you will need a copy of your systemui on your pc unzip it inside navigate to
res drawable-xhdpi folder you will need this as reference to name your new icons. Unzip the file attached to this post on your pc as well.
Find the icons you wish to use and place them in the systemui res drawable-xhdpi folder that is in the zip I provided make sure to name them exactly as they are named in the origional systemui folder when you have all your icons zip the xml file and the folder and follow the instructions above.
Please do this at your own risk I am not responsible if you brick your phone or anything else.
Statusbar icons that were used in my set up are now attached
For data signal only 4g is themed because that is all I needed I don't get lte and very seldom drop of 4g well actually I have never dropped off 4g since I had the phone. The saturn icons were made by me the other icons were from various sources so credt to those who made them.
Here's a screen shot of mine to show what can be done.
Using nova launcher and stock deodexed sense