* Remove the front differential: This is often necessary to gain enough clearance to access the oil pan bolts. This is a substantial undertaking itself.
* Lower the suspension: Lowering the front suspension will improve access, though it may not be enough on its own.
* Use a combination of jack stands, ramps, and possibly a hoist: You'll need to securely support the truck while working underneath.
* Have the right tools: Expect to need various socket extensions, ratchet wrenches, possibly air tools, and potentially a breaker bar for stubborn bolts.
* Be prepared for tight spaces: Working in cramped conditions under the truck is inevitable. This demands patience and dexterity.
* Possibly remove components: Some smaller components, like the skid plate or exhaust components may need partial removal or loosening for better access.
In summary: While technically possible, changing the oil pan on a 1995 Chevy 2500 HD 4x4 without removing the engine is a challenging job requiring significant mechanical skills and tools. It's far more labor-intensive than the job on most cars or even some smaller trucks. If you're not comfortable with advanced automotive repair, it's strongly recommended to seek professional help. The time saved from not removing the engine might be offset significantly by the increased difficulty and potential for damaging other components.
