Replacing hardlines is a PITA, but if they're rusted inside there's no alternative. If it's just a crimp or two, it's usually easier to cut out the crimped section, install fittings on the clean tube ends, and install a flex hose between the ends.
For doing tubing, you'll need a bender with proper jigs, seamless steel (not stainless) tubing of exact size, and flaring tool with fittings.
Buy extra tubing and fittings, and practice to get a feel for the tool to avoid crimping your final lines.
The PITA is measuring and placing bends in just the right places, at just the right angles.
You can cut-out the old lines, then use them as a pattern to make the replacements. Since they bend in three dimensions, getting the new lines to match isn't easy.
Above all, keep the ends securely plugged and avoid all contamination. A single grain of sand will eventually plug a tiny passage.
Check with NAPA, they might have pre-fitted replacement tubing available for your XJ by special order.