I lost power on my diesel my mechanic diagnosed my engine he said the turbo is bad and needs to be updated so I need a new manifold also. Cant I just replace the turbo with a rebuilt one? He also say's it needs timing belt update and the EGR is bad $4,500 total. I would like to find a repair manual for a 2005 jeep liberty crd 2.8l I have searched but can only find one for gas. If anyone can point me in the right direction it would be a big help.

First off where are you so maybe we can find you a mechanic that has a clue. Second, look "up" from where you post is to Sam's NOOB guide which you should read and while you are reading follow Sam's link to the FSMs (get both 05 and 06 as 05 lacks diesel cooling data and diagnostics but has illustration keys while 06 is the reverse).

Now your apparent issues and what the "mechanic" says:
1. there are a variety of reasons to lose power (bad CAC hoses $250 if torn or has holes or is oil soaked, bad boost pressure solenoid maybe $50, stuck turbo vanes cleaning is essentially free, dirty MAP sensor cleaning is essentially free and GM replacement is ca. $20, etc.) that don't mean the turbo is shot. In fact if you pull of the airbox to turbo hose, should do this anyway to check for tears on bottom just in front of turbo, and grab the "impeller" if it has only slight fore/aft play and barely perceptible side to side play the turbo is fine. When the turbos die it's pretty obvious and can pump all the oil out of your engine. So first thing you should do is check for play, if none to speak of turbo is fine look elsewhere for power loss.
2. there in NO SUCH THING as a CRD turbo "update" (other than the GDE Stage II turbo of course) and by extension anyone trying to sell you a manifold to go with the mythical turbo update must have a really big boat payment due. Even the GDE Stage II turbo bolts right up to the stock manifold.
3. that said a new, quality rebuilts don't exist yet although Garrett is starting to rebuild turbos for some models but not the CRD, turbo runs ca. $1,200 if needed. Some other minor parts go with the job but it's not a hard DIY so long as you take ample time to soak the 4 bolts on the mounting studs.
4. timing belt should be replaced at or near 100K miles or if you are not there yet about now anyway due to age. Belt costs $75 or so on Amazon and idlers are ca. $35 each or you can spring for a full kit ($400 or so) from IDparts which includes the water pump. For someone who knows what they are doing, critical, the TB is a ca. 3 hr job and the WP might add an hour or 2.
5. bad EGR is an all too typical diagnosis. Not to say an EGR cannot go bad but they are not all that hard to clean and if you spring for a GDE tune the EGR pretty much becomes irrelevant.

Other than checking your turbo for play I'd suggest you post detailed symptoms here along with any CEL codes before spending that kind of money.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

Thanks pappaindigo I will check out Sam's noob guide it will get me started.